Authorization Bypass Vulnerability in LangGraph API by LangChain AI
CVE-2026-118668

8.6HIGH

Key Information:

Vendor

Langchain-ai

Status
Langgraph-api
Vendor
CVE Published:
28 October 2026

What is CVE-2026-118668?

The LangGraph API, designed for rapid development and testing, is affected by an authorization bypass vulnerability due to a flaw in custom authentication Store authorization handlers. From versions 0.1.2 to 0.15.0, these handlers may return a rewritten namespace that isn't properly secured across runtime boundaries. This can potentially allow an authenticated user to gain access to another user's Store namespace, undermining privacy and data integrity. By exploiting this vulnerability, unauthorized actions such as reading, overwriting, searching, or deleting can occur. It's important to note that Python-based custom authentication handlers that effectively reject unauthorized namespaces are not impacted. The issue has been resolved in version 0.15.0.

Affected Version(s)

langgraph-api >= 0.1.2, < 0.15.0

References

https://github.com/langchain-ai/langgraph/security/adviso...
x_refsource_CONFIRM

CVSS V4

Score:
8.6
Severity:
HIGH
Confidentiality:
High
Integrity:
High
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.