#VU118093 Resource exhaustion in vLLM - CVE-2025-48956

Vulnerability identifier: #VU118093

Vulnerability risk: Medium

CVSSv4.0: 6.6 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2025-48956

CWE-ID: CWE-400

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
vLLM
Universal components / Libraries / Libraries used by multiple products

Vendor: vLLM

Description

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to application does not properly control consumption of internal resources when parsing HTTP header values. A remote attacker can send a specially crafted HTTP request with an overly large header value (e.g. for X-Forwarded-For header) to trigger resource exhaustion and perform a denial of service (DoS) attack.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

vLLM: 0.1.0 - 0.10.1

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External links
https://github.com/vllm-project/vllm/commit/d8b736f913a59117803d6701521d2e4861701944
https://github.com/vllm-project/vllm/pull/23267
https://github.com/vllm-project/vllm/security/advisories/GHSA-rxc4-3w6r-4v47

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.