vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of GHSA-rwxx-mrjm-wc2m — GHSA-48JH-3GJ7-FG8V

Summary

### Summary The fix for `GHSA-rwxx-mrjm-wc2m` ("ReDoS via `structured_outputs.regex` compiled without timeout") wrapped the regex compile in the **xgrammar** and **outlines** backends with `compile_regex_with_timeout` (and, for outlines, `validate_regex_is_buildable`). The **lm-format-enforcer** backend was left unguarded: it compiles the attacker-supplied regex with no timeout and no buildability check. A single…

Timeline

Published by source

2026-09-04

Risk context

• Reported severity or threat level: medium.
• Reported CVSS score: 5.3 out of 10.
• Reported EPSS value: 0.00315.
• Review exposure for the affected product or family: pip: vllm.

Product

pip: vllm

What to do

General, cautious steps (verify details in the official source):

• Review exposure and plan remediation based on risk and environment.
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

• Read the official source
• CVE Record
• NVD

Evidence and provenance

Canonical advisory ID

GHSA-48JH-3GJ7-FG8V

Source

GitHub

Vendor

GitHub

Published by source

2026-09-04

Last source activity

2026-09-04

Additional identifiers

CVE-2026-73556

Curated by

hlukh.ch

Related advisories and connections

These advisories are connected by shared CVE, product, vendor, source, or time signals.