Vulnerability · Published Mar 20, 2025 · Assigned by @huntr_ai
CVE-2024-10907Denial of Service (DoS) via Multipart Boundary in lm-sys/fastchat
High 7.5
In plain English
A high-severity infinite loop in lm-sys/fastchat from lm-sys. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 53% of all known vulnerabilities).
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| PyPI | fschat | no fix listed | GHSA-qg86-f892-m4hj |
| PyPI | fschat | no fix listed | PYSEC-2026-1398 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| lm-sys | lm-sys/fastchat | unspecified – through latest |
Weakness: CWE-835 · Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H