CVE-2026-51883

Critical severity, CVSS 9.1. EPSS: 0.3% chance of exploitation in the next 30 days.

The knowledge base creation and document upload interfaces in Langchain-Chatchat 0.3.0;0.3.1 is vulnerable to path traversal. An attacker can inject path traversal sequences (such as `..\`) into the `knowledge_base_name` parameter to write knowledge base content to arbitrary locations outside the configured knowledge base root directory.

Published 2026-10-01. Last modified 2026-10-05.