FastChat Uncontrolled Resource Consumption vulnerability
High severity
GitHub Reviewed
Published
Mar 20, 2025
to the GitHub Advisory Database
•
Updated Oct 15, 2025
Description
Published by the National Vulnerability Database
Mar 20, 2025
Published to the GitHub Advisory Database
Mar 20, 2025
Reviewed
Mar 21, 2025
Last updated
Oct 15, 2025
In lm-sys/fastchat Release v0.2.36, the server fails to handle excessive characters appended to the end of multipart boundaries. This flaw can be exploited by sending malformed multipart requests with arbitrary characters at the end of the boundary. Each extra character is processed in an infinite loop, leading to excessive resource consumption and a complete denial of service (DoS) for all users. The vulnerability is unauthenticated, meaning no user login or interaction is required for an attacker to exploit this issue.
References