- Critical 9.8
CVE-2026-51884
The /knowledge_base/upload_temp_docs temporary document upload endpoint in Langchain Chatchat 0.3.1 is vulnerable to path traversal. By crafting malicious filenames, an attacker can write files to arbitrary locations on the server, bypassing the intended restrictions on the temporary directory.
Scores
The facts
- Published
- 1 October 2026
- Last changed
- 5 October 2026
- NVD status
- Deferred
- Severity
- Critical, CVSS 9.8 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H - Weakness
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 0.5% chance of exploitation activity in the next 30 days (percentile 42).
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