CVE-2026-51882

Critical severity, CVSS 9.1. EPSS: 0.4% chance of exploitation in the next 30 days.

The OpenAI-compatible file upload endpoint `/v1/files` in Langchain-Chatchat 0.3.0 is vulnerable to path traversal. An attacker can write files to arbitrary locations outside the `openai_files` directory by crafting malicious filenames.

Published 2026-10-01. Last modified 2026-10-07.