vLLMGHSA-wc36-9694-f9rf
vLLM Denial of Service via the best_of parameter
No fix yet
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
| Package | Affected | Fixed in |
|---|---|---|
| vllm PyPI | <= 0.5.0.post1 | No 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