Vulnerability · Published May 30, 2025 · Assigned by GitHub_M

CVE-2025-48943vLLM allows clients to crash the openai server with invalid regex

Medium 6.5

In plain English

A medium-severity security flaw in vllm from vllm-project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 44% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium

Exploit odds (30 days)0.5%top 56.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

vLLM is an inference and serving engine for large language models (LLMs). Version 0.8.0 up to but excluding 0.9.0 have a Denial of Service (ReDoS) that causes the vLLM server to crash if an invalid regex was provided while using structured output. This vulnerability is similar to GHSA-6qc9-v4r8-22xg/CVE-2025-48942, but for regex instead of a JSON schema. Version 0.9.0 fixes the issue.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	vllm	0.9.0	GHSA-9hcf-v7m4-6m2j
PyPI	vllm	0.9.0	PYSEC-2025-55

Affected products (as reported)

Vendor	Product	Versions
vllm-project	vllm	>= 0.8.0, < 0.9.0

Weakness: CWE-248 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

References

https://github.com/vllm-project/vllm/security/advisories/GHSA-9hcf-v7m4-6m2j x_refsource_CONFIRM
https://github.com/vllm-project/vllm/issues/17313 x_refsource_MISC
https://github.com/vllm-project/vllm/pull/17623 x_refsource_MISC
https://github.com/vllm-project/vllm/commit/08bf7840780980c7568c573c70a6a8db94fd45ff x_refsource_MISC