CVE-2026-55236: langchain-ai langgraph-api · Improper Authorization
Affects langchain-ai langgraph-apiSource CVE Database V5
Not known to be exploited · CVSS 5.9 Medium : upgrade to 0.10.0 when convenient.
Data as of 29 Oct 2026, 19:04 UTC
- EPSS
- 0.2% chance of exploitation in 30 days – higher than 17% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- Patch
- Available – fixed in 0.10.0
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:NExploitation evidence
Disclosed: evidence found.
CVE published 14 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade langgraph-api and langchain-ai/langgraph-api to 0.10.0.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| langchain-ailanggraph-api | Affected
| Fixed in
|
GitHublangchain-ai/langgraph-apipkg:github/langchain-ai/langgraph-apiOther threats | Affected
| Fixed in
|
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AI-suggested
This vulnerability is fixed in langgraph-api version 0.10.0. Users should upgrade to version 0.10.0 or later to remediate this issue. Deployments that have custom authorization handlers applying an owner filter to all assistant events or a global fallback handler are not affected. Patch status is confirmed fixed in 0.10.0.
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.