- Critical 9.1
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.
Scores
The facts
- Published
- 1 October 2026
- Last changed
- 5 October 2026
- NVD status
- Deferred
- Severity
- Critical, CVSS 9.1 out of 10 (version 3.1)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N - Weakness
- Known exploited
- Not in the CISA Known Exploited Vulnerabilities catalogue in this build.
- EPSS
- 0.3% chance of exploitation activity in the next 30 days (percentile 27).
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