vLLM: ReDoS via structured_outputs.regex compiled without timeout in xgrammar and outlines backends

Date Jul 17, 2026
Type Vendor advisory
Signal High-risk advisory
Vendor / Product PyPI ยท vllm
CVE CVE-2026-55574
High-risk advisory CVE-2026-55574

Summary

vLLM: ReDoS via structured_outputs.regex compiled without timeout in xgrammar and outlines backends

Why it matters

GitHub has published a reviewed security advisory for vllm. Prioritize it with other application dependency updates, especially because EPSS places it in the 25% percentile.

Operator check

Check whether vllm is present in application dependency manifests, lockfiles, or build images. Review the GitHub advisory and upgrade to a patched version where available. CVSS score: 8.7. EPSS probability: 0.3%; percentile: 25%.

Sources

PatchBrief uses public sources. It does not scan environments, verify exposure, or replace vendor guidance.