What’s Vulnerable › Vulnerabilities

CVE-2026-118667: LangGraph: Unencoded identifiers in LangGraph SDK v3 streaming can redirect authenticated GET requests

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-10-28 · updated 2026-10-29
• Weakness: CWE-22

Description

LangGraph Python SDK is used to connect to running LangGraph API servers, manage assistants, threads and stream runs from Python applications. From langgraph-sdk 0.4.0 until 0.4.6, and from langgraph 1.2.3 until 1.2.14 when RemoteGraph v3 streaming uses an affected langgraph-sdk version, the synchronous and asynchronous v3 stream get_tree and _fetch_state helpers interpolate caller-controlled assistant_id and thread_id values into authenticated GET request paths without using _quote_path_param. Relative path segments can therefore be normalized into another readable path on the configured server while retaining authentication headers. This issue is fixed in langgraph-sdk 0.4.6 and langgraph 1.2.14.

Affected products

• langchain-ai langgraph: from 1.2.3, < 1.2.14
• @langchain Langgraph-Sdk: from 0.4.0, < 0.4.6

References

• https://github.com/langchain-ai/langgraph/commit/d89c7e100ec6fc1512544d23b0a7c5169699ef3e
• https://github.com/langchain-ai/langgraph/pull/9213
• https://github.com/langchain-ai/langgraph/releases/tag/1.2.14
• https://github.com/langchain-ai/langgraph/releases/tag/sdk%3D%3D0.4.6
• https://github.com/langchain-ai/langgraph/security/advisories/GHSA-3fx2-cqw9-xr3c

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