Vulnerability · Published Jun 20, 2026 · Assigned by VulnCheck

CVE-2025-71379vllm - Regular Expression Denial of Service in Multiple Components

Medium 4.3

In plain English

A medium-severity regular-expression denial of service in vllm from vllm. 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 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.5%top 58.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

vLLM versions >= 0.6.3 and < 0.9.0 contain multiple regular expression denial of service (ReDoS) vulnerabilities. Several regex patterns — in vllm/lora/utils.py, the phi4mini tool parser, and the OpenAI-compatible serving chat endpoint — are susceptible to catastrophic backtracking. An attacker submitting crafted input with nested or repeated structures can trigger severe CPU consumption and performance degradation, resulting in denial of service.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
PyPI	vllm	0.9.0	GHSA-j828-28rj-hfhp

Affected products (as reported)

Vendor	Product	Versions
vllm	vllm	0.6.3 – before 0.9.0

Weakness: CWE-1333 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:L

References

GHSA Advisory GHSA-j828-28rj-hfhp vendor-advisory
VulnCheck Advisory: vllm - Regular Expression Denial of Service in Multiple Components third-party-advisory