What is CVE-2026-118667?

CVE-2026-118667 is a medium-severity vulnerability in Langchain-Ai Langgraph, classified under Path Traversal. CVSS score: 4.3/10. Published 2026-10-28.

How severe is CVE-2026-118667?

Medium severity. CVSS v3 base score is 4.3 out of 10.

Path Traversal in Langchain-Ai Langgraph

CVE-2026-118667

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.

Vulnerability class: Path Traversal (Directory Traversal)

Published 2026-10-28.

CVSS v3 metric

CVSS v3 base score 4.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Langchain-Ai Langgraph — versions >= 1.2.3, < 1.2.14
Langchain-Ai Langgraph-Sdk — versions >= 0.4.0, < 0.4.6

Weakness classification (CWE)

CWE-22 — Path Traversal

References

Frequently asked questions

What is CVE-2026-118667?: CVE-2026-118667 is a medium-severity vulnerability in Langchain-Ai Langgraph, classified under Path Traversal. CVSS score: 4.3/10. Published 2026-10-28.
How severe is CVE-2026-118667?: Medium severity. CVSS v3 base score is 4.3 out of 10.