AI and data stack advisories

Severe, 6 weeks1498Projects326

1498 severe, 6 weeks · 326 projects

vLLMGHSA-wc36-9694-f9rf

vLLM Denial of Service via the best_of parameter

vLLM

CVE-2024-8939 · Published Sep 17, 2024 · updated Aug 7, 2026

Medium6.2
No fix yet
GitHub advisory

A vulnerability was found in the ilab model serve component, where improper handling of the best_of parameter in the vllm JSON web API can lead to a Denial of Service (DoS). The API used for LLM-based sentence or chat completion accepts a best_of parameter to return the best completion from several options. When this parameter is set to a large value, the API does not handle timeouts or resource exhaustion properly, allowing an attacker to cause a DoS by consuming excessive system resources. This leads to the API becoming unresponsive, preventing legitimate users from accessing the service.

Affected versions

PackageAffectedFixed in
vllm
PyPI
<= 0.5.0.post1No fix yet
Details and references
CVSS 3.1
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity from
GitHub (reviewed advisory)
Weakness
CWE-400
Also known as
CVE-2024-8939, PYSEC-2026-2025

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