lm-sys/fastchat · Security
FastChat has a Content Moderation Bypass via Arena Side-by-Side Views
- GHSA ID
- GHSA-f3q6-69f3-vwch
- CVE ID
- CVE-2026-6608
- Severity
- medium
- Published
- Updated
- CVSS
- 5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CVSS v3
- 5.3 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
- CVSS v4
- 5.5 · CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:P
Description
A vulnerability was detected in lm-sys fastchat up to 0.2.36. Impacted is the function add_text of the component Arena Side-by-Side View Handler. The manipulation results in incorrect control flow. The attack can be launched remotely. The exploit is now public and may be used. The root cause was fixed in commit 34eca62 for gradio_block_arena_named.py, but three other files were missed.
CWEs
- CWE-670 · Always-Incorrect Control Flow Implementation
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-6608 ↗
- https://github.com/lm-sys/FastChat/issues/3834 ↗
- https://gist.github.com/YLChen-007/e45039d23e698222d887ee09735d9d36 ↗
- https://github.com/lm-sys/FastChat ↗
- https://vuldb.com/submit/792228 ↗
- https://vuldb.com/vuln/358243 ↗
- https://vuldb.com/vuln/358243/cti ↗
- https://github.com/advisories/GHSA-f3q6-69f3-vwch ↗