CVE-2025-3677: Lm-Sys Fastchat

Medium severity, CVSS 5.3. EPSS: 0.2% chance of exploitation in the next 30 days.

A vulnerability classified as critical was found in lm-sys fastchat up to 0.2.36. This vulnerability affects the function split_files/apply_delta_low_cpu_mem of the file fastchat/model/apply_delta.py. The manipulation leads to deserialization. An attack has to be approached locally.

Affected products

• Lm-Sys Fastchat: version 0.2.0 only; version 0.2.1 only; version 0.2.2 only; version 0.2.3 only; version 0.2.4 only; version 0.2.5 only; …

Published 2025-04-16. Last modified 2026-06-17.