Summary
LangGraph JavaScript custom authentication may permit cross-user Store access
LangGraph deployments using JavaScript or TypeScript custom authentication may fail to apply Store authorization changes returned by an authorization handler. In affected deployments, an authenticated user may be able to access Store data outside their authorized namespace.
Required conditions
A deployment is affected only when all of the following conditions apply:
- It uses an affected
langgraph-apiversion. - It runs JavaScript or TypeScript custom authentication.
- Its Store authorization handler relies on rewriting the requested namespace to restrict each user to their own data.
- The attacker can authenticate as an ordinary user.
- Multiple users' data is stored through the affected authorization path.
Python custom authentication handlers are not affected. JavaScript or TypeScript handlers that reject unauthorized namespace requests instead of rewriting them are also not affected.
The attack does not require administrator privileges, user interaction, a race condition, or the bypass of another mitigation.
Workarounds
Deployments that cannot upgrade immediately should change JavaScript or TypeScript Store authorization handlers to reject requests for unauthorized namespaces rather than relying on namespace rewriting.
This workaround must be applied to every Store action exposed by the deployment.
Impact
An authenticated user may be able to read, overwrite, search, or delete Store data belonging to another user.
The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions. Typical impact: unauthorized data access or execution of privileged operations.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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The issue is fixed in langgraph-api version 0.15.0. The server now carries changes made by a JavaScript or TypeScript authorization handler across the runtime boundary and applies them before performing the Store operation. It validates the resulting namespace after authorization and rejects the request if an authorization change is malformed or cannot be applied safely.
Users should upgrade to langgraph-api>=0.15.0.
Frequently Asked Questions
- What is CVE-2026-118668? CVE-2026-118668 is a high-severity incorrect authorization vulnerability in langgraph-api (pip), affecting versions >= 0.1.2, < 0.15.0. It is fixed in 0.15.0. The application does not correctly enforce access controls, allowing a principal to access resources or operations beyond their granted permissions.
- Which versions of langgraph-api are affected by CVE-2026-118668? langgraph-api (pip) versions >= 0.1.2, < 0.15.0 is affected.
- Is there a fix for CVE-2026-118668? Yes. CVE-2026-118668 is fixed in 0.15.0. Upgrade to this version or later.
- Is CVE-2026-118668 exploitable, and should I be worried? Whether CVE-2026-118668 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-118668 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-118668? Upgrade
langgraph-apito 0.15.0 or later.