CVE-2026-55574

HIGHNVD 7.57.5—
EchelonGraph scoreMEDIUM confidence

This high-severity CVE scores 7.5 under NVD CVSS v3. EPSS exploit probability: 0.3%, top 76% of all CVEs by exploit prediction. GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).

Triggered by: NVD CVSS baseline
Sources: epss, nvd
Trending — 4 sources updated this week
7.5
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: 0%CVSS: 7.5Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Prior to 0.24.0, the structured_outputs.regex API parameter passes a user-supplied regular expression string directly to the grammar compiler backends with no compilation timeout; in the xgrammar backend the string reaches the regex compiler with no guard, and in the outlines backend the validation step blocks structural issues such as lookarounds and backreferences but performs no complexity analysis, so a pattern with nested quantifiers passes all checks and causes exponential state-space expansion, allowing a single request containing an adversarial regex to hang an inference worker indefinitely and deny service. This issue is fixed in version 0.24.0.

CVSS v3
7.5
EG Score
7.5(medium)
EPSS
24.4%
KEV
Not listed

Published

July 6, 2026

Last Modified

July 7, 2026

Advisory Details (3)

Auto-updated Jul 6, 2026
Patch available. Sources: github_commit, github_pr, github.
github Patch Available

ReDoS via structured_outputs.regex compiled without timeout in xgrammar and outlines backends · Advisory · vllm-project/vllm · GitHub

https://github.com/vllm-project/vllm/security/advisories/GHSA-rwxx-mrjm-wc2m
github_pr

[Security] Add timeout guard for regex compilation in structured outp…

Fix merged in vllm-project/vllm PR #45118 on 2026-06-13 — awaiting tagged release

https://github.com/vllm-project/vllm/pull/45118
github_commit

commit 2b3006076c5e (vllm-project/vllm)

Fix landed in vllm-project/vllm commit 2b3006076c5e — awaiting tagged release

https://github.com/vllm-project/vllm/commit/2b3006076c5e9bc4cda9e03e3641388de3c5c286

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 22× in last 7d / 22× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-12 05:25 UTCEG score recompute
  2. 2026-07-11 17:42 UTCEG score recompute
  3. 2026-07-11 08:27 UTCEPSS rescore
  4. 2026-07-11 08:27 UTCEPSS rescore
  5. 2026-07-11 05:59 UTCEG score recompute
  6. 2026-07-10 18:17 UTCEG score recompute
  7. 2026-07-10 06:30 UTCEG score recompute
  8. 2026-07-09 19:10 UTCEPSS rescore
  9. 2026-07-09 19:10 UTCEPSS rescore
  10. 2026-07-09 18:48 UTCEG score recompute
  11. 2026-07-09 07:05 UTCEG score recompute
  12. 2026-07-08 19:22 UTCEG score recompute
  13. 2026-07-08 15:16 UTCEPSS rescore
  14. 2026-07-08 15:16 UTCEPSS rescore
  15. 2026-07-08 07:39 UTCEG score recompute▼ 1.20
  16. 2026-07-07 20:14 UTCNVD updateCVSS v3 → 7.5
  17. 2026-07-07 19:57 UTCEG score recompute
  18. 2026-07-07 13:46 UTCEPSS rescore
  19. 2026-07-07 13:46 UTCEPSS rescore
  20. 2026-07-07 08:14 UTCEG score recompute
  21. 2026-07-06 20:30 UTCEG score recompute
  22. 2026-07-06 20:29 UTCMITRE cvelistV5first tracked

Frequently asked(5)

What is CVE-2026-55574?
CVE-2026-55574 is a high vulnerability published on July 6, 2026. vLLM is a high-throughput and memory-efficient inference and serving engine for LLMs. Prior to 0.24.0, the structured_outputs.regex API parameter passes a user-supplied regular expression string directly to the grammar compiler backends with no compilation timeout; in the xgrammar backend the…
When was CVE-2026-55574 disclosed?
CVE-2026-55574 was first published in the National Vulnerability Database on July 6, 2026, with the most recent update on July 7, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-55574 actively exploited?
CVE-2026-55574 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 24.4% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-55574?
CVE-2026-55574 has a CVSS v3 base score of 7.5 (NVD).
How do I remediate CVE-2026-55574?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-55574, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

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