langgraph-sdk

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

The LangGraph Python SDK v3 streaming client interpolates caller-supplied thread_id and assistant_id values into request paths without encoding them at four synchronous and asynchronous call sites. Relative path segments can therefore redirect an authenticated GET request to another path on the same configured server.

Details

The affected get_tree and _fetch_state implementations build request paths from raw identifiers rather than passing each identifier through the SDK's existing _quote_path_param helper. HTTP path normalization can collapse values containing relative segments before dispatch while retaining the client's authentication headers.

langgraph-sdk versions 0.4.0 through 0.4.5 are affected. The v3 stream module is not present in the 0.3.x release line.

RemoteGraph v3 streaming in langgraph 1.2.3 and later is also affected when used with a vulnerable langgraph-sdk version. It passes config["configurable"]["thread_id"] into threads.stream(...), and its dependency range permits affected SDK versions.

Impact

An application is affected only if it passes attacker-controlled text as a streaming thread_id or assistant_id. In that configuration, an attacker may select another readable path on the configured server and cause the SDK to return that response to the application. Through thread_id, the attacker can also control the query string, for example by targeting /store/items?namespace=...&key=...; assistant_id controls only the path. The affected requests are GET operations, so this issue does not provide a write primitive.

The LangGraph Platform is not exposed to this issue.

Remediation

Upgrade langgraph-sdk to version 0.4.6 or later. The fix encodes assistant_id in get_tree and thread_id in _fetch_state with _quote_path_param in both synchronous and asynchronous stream modules.

If you use RemoteGraph, also upgrade langgraph to version 1.2.14 or later, which requires langgraph-sdk>=0.4.6.

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A

Summary

langgraph-sdk constructs HTTP request paths for resource operations by interpolating caller-supplied identifier values into URL templates. Without sanitization of those values, identifiers that contain characters with special meaning in URL paths could cause the resulting request to address a different resource (and potentially a different resource type) than the SDK method's call site indicates. In deployments where the SDK receives identifier values that originate from untrusted sources, this could result in unintended access, modification, or deletion of resources beyond the calling user's authorization scope.

This issue is most consequential in deployments that:

• forward end-user-supplied values directly into SDK identifier parameters without first validating them against an expected format (such as a UUID), and
• rely on URL-prefix-based authorization at an upstream layer (reverse proxy, edge gateway, WAF), where the authorization decision is made on the SDK call's intended path rather than on the final delivered request path.

There have no evidence of this behavior being triggered in the wild. This change is intended to reduce the surface available when caller-supplied identifier values originate from untrusted sources.

Affected users / systems

You may be affected if you:

• use langgraph-sdk (Python) to address resources by identifier, and
• pass identifier values into SDK methods that originate from end-user input, untrusted third-party callers, or any source that does not validate identifier format before the SDK call.

Applications that validate identifier values (for example, by parsing them as UUIDs and rejecting anything that does not parse) before passing them to SDK methods are not affected. Validated UUIDs round-trip through the SDK request path unchanged.

Impact

• Potential unintended access, modification, or deletion of resources via SDK methods called for a different resource type, when caller-supplied identifier values are not validated.
• In deployments with prefix-based authorization at an upstream layer, the authorization decision and the final delivered request path may diverge.
• Confidentiality: disclosure of resource content beyond the authorization scope of the calling user.
• Integrity: modification or deletion of resources beyond the authorization scope of the calling user.

Patches / mitigation

The SDK now applies path-segment encoding to identifier values before they are interpolated into request URL templates. After this change, identifier values that contain characters with special meaning in URL paths are transmitted as encoded byte sequences and routed to the resource the SDK method's call site indicates.

Compatibility

Identifier values that match the standard UUID format, or any other format that contains only characters safe to transmit unencoded in URL path segments, round-trip through the SDK request path unchanged. Applications that already validate identifier inputs see no behavioral change.

Operational guidance

• Validate identifier values (typically as UUIDs) at the boundary where untrusted input enters the application, before passing them to SDK methods.
• For deployments relying on URL-prefix-based authorization upstream of LangGraph, prefer authorization at the LangGraph server layer or on parsed-and-validated request paths rather than on raw URL prefixes.

LangSmith / hosted deployments note

This issue affects the SDK that runs in caller applications. The LangGraph server runtime, including LangSmith-hosted deployments, receives ordinary HTTP requests on documented routes and is not itself affected by this issue. Applications that consume LangSmith-hosted services via langgraph-sdk and pass untrusted identifier values to SDK methods should upgrade.

First reported by: pucagit (CyStack).

Impact

What kind of vulnerability is it? Who is impacted? langgraph-sdk incorrectly applies the actions= argument on resource-scoped authorization decorators, including @auth.on.threads, @auth.on.assistants, and @auth.on.crons.

In affected versions, a decorator such as:

@auth.on.threads(actions=["create"])
async def allow_thread_create(ctx, value):
    return None

intended to register a handler for selected actions instead registers that handler for every action on the resource. Because the resource-wide handler is selected before broader fallback handlers, authorization checks implemented in those fallback handlers may not run.

An authenticated user may therefore be able to perform actions the application intended to deny, such as reading, updating, or deleting another user's resource. Exploitability and impact depend on the affected handler's behavior: deployments remain protected if that handler independently enforces the necessary action, ownership, or permission checks for every request it receives.

Only Python deployments using actions= on the affected resource-scoped decorators are affected.

Patches

0.4.4

Workarounds

No.

References

N/A