CVE-2026-51883

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 Oct 1, 2026
• CVSS 9.1 critical
• 0.1% chance of exploitation in the next 30 days (EPSS)

CVE-2026-51883 at the National Vulnerability Database