CVE-2024-11603 Server-Side Request Forgery in lm-sys/fastchat

High 7.5 Published 20 Mar 2025 Updated 20 Mar 2025

An attacker can exploit insufficient validation in the /queue/join endpoint to access internal networks or AWS metadata, exposing sensitive data.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: None listed

What is CVE-2024-11603?

CVE-2024-11603 is a high-severity server-side request forgery vulnerability in lm-sys/fastchat, published on 20 Mar 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A Server-Side Request Forgery (SSRF) vulnerability exists in lm-sys/fastchat version 0.2.36. The vulnerability is present in the `/queue/join?` endpoint, where insufficient validation of the path parameter allows an attacker to send crafted requests. This can lead to unauthorized access to internal networks or the AWS metadata endpoint, potentially exposing sensitive data and compromising internal servers.

Weakness: CWE-918

Which versions are affected by CVE-2024-11603?

3 open source packages ship an affected version, including fschat. It affects 1 product.

Package	Affected	Fixed in
`fschat` PyPI	All versions to `0.2.36`	None
`fschat` PyPI	All versions to `0.2.36`	None
`fschat` PyPI	All versions to `0.2.36`	None

Products include Lm-Sys Fastchat.

How do I fix CVE-2024-11603?

No fix has been published for CVE-2024-11603 yet. Limit exposure of the affected software until one is available.

Upgrade, and send outbound requests through an allow-list that blocks internal addresses. More about Server-side request forgery.

Is CVE-2024-11603 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2024-11603 exists.

Sources

Also known as GHSA-h254-g997-685c, PYSEC-2026-1397.