CVE-2026-118668 LangGraph JavaScript custom authentication may permit cross-user Store access
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-118668?
CVE-2026-118668 is a high-severity vulnerability in langchain-ai langgraph-api, published on 28 Oct 2026.
Official description
langgraph-api implements the LangGraph API for rapid development and testing. From 0.1.2 until 0.15.0, JavaScript or TypeScript custom authentication Store authorization handlers can return a rewritten namespace that is not carried across the runtime boundary and applied before the Store operation. An authenticated user can therefore access another user's Store namespace when a deployment relies on namespace rewriting for isolation, allowing unauthorized reads, overwrites, searches, or deletions. Python custom authentication and handlers that reject unauthorized namespaces instead of rewriting them are not affected. This issue is fixed in version 0.15.0.
Which versions are affected by CVE-2026-118668?
2 open source packages ship an affected version, including langgraph-api.
| Package | Affected | Fixed in |
|---|---|---|
langgraph-api PyPI | From 0.1.2 | 0.15.0 |
langgraph-api PyPI | From 0.1.2 | 0.15.0 |
How do I fix CVE-2026-118668?
Upgrade langgraph-api to 0.15.0 or later.
Is CVE-2026-118668 being exploited?
There is no known exploitation of CVE-2026-118668 in the wild and no public exploit code.
Sources
Also known as GHSA-4hm6-w6qq-w73v.