GHSA-rxc4-3w6r-4v47
vllm API endpoints vulnerable to Denial of Service Attacks
Packages
Details
As written in the advisory (Markdown source, shown as plain text).
### Summary
A Denial of Service (DoS) vulnerability can be triggered by sending a single HTTP GET request with an extremely large header to an HTTP endpoint. This results in server memory exhaustion, potentially leading to a crash or unresponsiveness. The attack does not require authentication, making it exploitable by any remote user.
### Details
The vulnerability leverages the abuse of HTTP headers. By setting a header such as `X-Forwarded-For` to a very large value like `("A" * 5_800_000_000)`, the server's HTTP parser or application logic may attempt to load the entire request into memory, overwhelming system resources.
### Impact
_What kind of vulnerability is it? Who is impacted?_
Type of vulnerability: Denial of Service (DoS)
### Resolution
Upgrade to a version of vLLM that includes appropriate HTTP limits by deafult, or use a proxy in front of vLLM which provides protection against this issue.
References
External links from the advisory. They lead to third-party sites.
- https://github.com/vllm-project/vllm/security/advisories/GHSA-rxc4-3w6r-4v47
- https://nvd.nist.gov/vuln/detail/CVE-2025-48956
- https://github.com/vllm-project/vllm/pull/23267
- https://github.com/vllm-project/vllm/commit/d8b736f913a59117803d6701521d2e4861701944
- https://github.com/advisories/GHSA-rxc4-3w6r-4v47
- https://github.com/pypa/advisory-database/tree/main/vulns/vllm/PYSEC-2026-2021.yaml
- https://github.com/vllm-project/vllm
- https://pypi.org/project/vllm