CVE-2026-104873: langgraph-sdk Custom Auth Bypass Vulnerability
Summary
CVE-2026-104873: LangGraph SDK custom auth silently ignores actions= on resource decorators. Affects langgraph-sdk versions >= 0.1.45, < 0.4.4. Fixed in 0.4.4. How to fix ↓
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Background
The langgraph-sdk is a Python library designed for building applications that utilize language models. It provides various decorators for resource-scoped authorization, allowing developers to manage permissions effectively. However, a flaw in the implementation of these decorators can lead to unauthorized access to sensitive actions within the application.
Vulnerability Detail
The langgraph-sdk contains a vulnerability where the 'actions=' argument in resource-scoped authorization decorators, such as @auth.on.threads, @auth.on.assistants, and @auth.on.crons, is incorrectly applied. This misconfiguration allows a handler intended for specific actions to register for all actions on the resource. As a result, an authenticated user may perform actions that should be denied, such as reading, updating, or deleting another user's resources. The impact of this vulnerability is contingent on the behavior of the affected handler, which may or may not enforce necessary permission checks independently.
How To Fix
Latest published version: 0.4.8 as of 23 Oct 2026
pip install --upgrade "langgraph-sdk==0.4.8"Upgrading to it may include breaking changes; the version below is the minimum fixed release for this vulnerability.
If you need the minimum change
0.4.4
This is the first release that contains the fix.
pip install --upgrade "langgraph-sdk==0.4.4"Tip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
There are currently no workarounds available for this vulnerability. It is recommended to update to the patched version as soon as possible.
Conclusion
The langgraph-sdk vulnerability CVE-2026-104873 poses a significant risk to applications using this library for authorization. It is crucial to update to version 0.4.4 or later to mitigate the risk of unauthorized access to sensitive actions.
See every vulnerability recorded for langgraph-sdk →
FAQ
CVE-2026-104873 is a vulnerability in the langgraph-sdk that allows unauthorized actions due to incorrect application of authorization decorators.
Only Python deployments using the langgraph-sdk with the 'actions=' argument on affected resource-scoped decorators are impacted.
An authenticated user may exploit this vulnerability to read, update, or delete resources that they should not have access to.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without needing to sign up.
The CVSS score of this vulnerability is 7.6, indicating a high severity level.
References
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