MEDIUM5.3
PYSEC-2026-2485
FastChat has a Content Moderation Bypass via Arena Side-by-Side Views
Details
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.
Are you affected?
Enter the version of the package you're using.
Affected packages
PyPI/fschat
Introduced in:
0No fixed version published yet for fschat (pip). Pin to a known-safe version or switch to an alternative.
References
- https://nvd.nist.gov/vuln/detail/CVE-2026-6608[ADVISORY]
- https://github.com/lm-sys/FastChat/issues/3834[WEB]
- https://gist.github.com/YLChen-007/e45039d23e698222d887ee09735d9d36[WEB]
- https://github.com/lm-sys/FastChat[PACKAGE]
- https://vuldb.com/submit/792228[WEB]
- https://vuldb.com/vuln/358243[WEB]
- https://vuldb.com/vuln/358243/cti[WEB]
- https://pypi.org/project/fschat[PACKAGE]
- https://github.com/advisories/GHSA-f3q6-69f3-vwch[ADVISORY]