# CVE-2026-55236: langgraph-api: Incomplete assistant authorization in LangGraph Server run creation

> CVE-2026-55236: langgraph-api: Incomplete assistant authorization in LangGraph Server run creation. CVSS 5.9 (CVSS 3.1).

Canonical: https://rewindex.com/cve/CVE-2026-55236
Last updated: 2026-09-30T19:57:08Z

- Published: 2026-09-14 15:51 UTC · Updated: 2026-09-30 19:57 UTC · Assigner: GitHub\_M
- CVSS: 5.9 (CVSS 3.1) · Severity: Medium · Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:N
- EPSS: 0.26%, 17th percentile (scored 2026-11-05)
- CISA KEV: no
- CWE: CWE-285

## Description

langgraph-api implements the LangGraph API for rapid development and testing. Prior to 0.10.0, the langgraph-api run-creation path authorizes the assistant attached to a run by dispatching assistants.search with an incomplete value instead of the assistants.read event used by direct reads and cron creation. In deployments with custom resource handlers that register only assistants.read, omit an assistants.search handler, and have no global fallback handler, no applicable handler supplies an owner filter, allowing a low-privileged user to reference another user's private assistant through POST /runs or POST /threads/{thread\_id}/runs. The run-creation response can disclose the private assistant's metadata, config, and context, and the run can execute using that assistant's configuration. Deployments without custom authorization handlers, or with an equivalent owner filter applied through a global handler or across all assistant events, are not affected. This issue is fixed in version 0.10.0.

## Affected vendors and products

- langchain-ai: langgraph-api

## Tracked companies

- [LangChain (LangSmith)](https://rewindex.com/company/langchain-langsmith.md)

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2026-55236)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2026-55236)
- [https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx](https://github.com/langchain-ai/docs/blob/7b70fbacab21f84d9c6f9848f86cdeb471adbb50/src/langsmith/agent-server-changelog.mdx)
- [https://github.com/langchain-ai/helm/security/advisories/GHSA-jfj5-wrj9-63x4](https://github.com/langchain-ai/helm/security/advisories/GHSA-jfj5-wrj9-63x4)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2026-55236 · Markdown: https://rewindex.com/cve/CVE-2026-55236.md · JSON: https://rewindex.com/api/v1/cves/CVE-2026-55236 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-11-05T18:42:23.541Z