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TI-2026-40113 Aliases CVE-2026-55574GHSA-rwxx-mrjm-wc2m

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

Priority LOW 38CWE-1333Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Partial Red Hat: 4 fixed, 3 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-1333.

Summary

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00583 48th percentileScored 2026-11-07
Fix Partial vllm (vllm-project): 0.24.0vllm (PyPI): 0.24.0Red Hat: 13 advisoriesRed Hat: 4 fixed, 3 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
vllm-projectvllmbefore 0.24.00.24.0Patch availableCNA
—vllm (PyPI)before 0.24.00.24.0Patch availableGHSA-rwxx-mrjm-wc2m
  • vllm Vendorvllm-project Affected before 0.24.0 Fixed in 0.24.0 Patch available CNA
  • vllm (PyPI) Vendor— Affected before 0.24.0 Fixed in 0.24.0 Patch available GHSA-rwxx-mrjm-wc2m

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:*before 0.24.0VulnerablevLLM
  • cpe:2.3:a:vllm:vllm:*:*:*:*:*:*:*:* Versions before 0.24.0 Vulnerable ·vLLM

Remediation

  • Fix · CNA vllm (vllm-project) Fixed in 0.24.0
  • Fix · GHSA-rwxx-mrjm-wc2m vllm (PyPI) Fixed in 0.24.0 Advisory →

Red Hat 13 advisories

  • RHSA-2026:76150 Released 2026-10-05 · Red Hat rating Important
    Red Hat Enterprise Linux AI 3.4.5 security update
    • Red Hat Enterprise Linux AI 3.4 registry.redhat.io/rhelai3/bootc-aws-cuda-rhel9, registry.redhat.io/rhelai3/bootc-azure-cuda-rhel9, registry.redhat.io/rhelai3/bootc-azure-rocm-rhel9 +3
  • RHSA-2026:76149 Released 2026-10-05 · Red Hat rating Important
    Red Hat Enterprise Linux AI 3.4.5 security update
    • Red Hat Enterprise Linux AI 3.4 registry.redhat.io/rhelai3/disk-image-cuda-rhel9
  • RHSA-2026:70995 Released 2026-09-23 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (rocm)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-rocm-rhel9
Show 10 more Red Hat advisories
  • RHSA-2026:70979 Released 2026-09-23 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (cuda)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cuda-rhel9
  • RHSA-2026:70969 Released 2026-09-23 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (spyre)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-spyre-rhel9
  • RHSA-2026:70965 Released 2026-09-23 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (cpu)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cpu-rhel9
  • RHSA-2026:69469 Released 2026-09-21 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (rocm)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-rocm-rhel9
  • RHSA-2026:69467 Released 2026-09-21 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (cuda)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cuda-rhel9
  • RHSA-2026:69466 Released 2026-09-21 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (cpu)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-cpu-rhel9
  • RHSA-2026:69464 Released 2026-09-21 · Red Hat rating Important
    Red Hat AI Inference 3.4.5 (spyre)
    • Red Hat AI Inference Server 3.4 registry.redhat.io/rhaii/vllm-spyre-rhel9
  • RHSA-2026:61629 Released 2026-08-31 · Red Hat rating Important
    Red Hat AI Inference Server 3.2.2 (ROCm)
    • Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/vllm-rocm-rhel9
  • RHSA-2026:61627 Released 2026-08-31 · Red Hat rating Important
    Red Hat AI Inference Server 3.2.2 (CUDA)
    • Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/vllm-cuda-rhel9
  • RHSA-2026:60363 Released 2026-08-26 · Red Hat rating Important
    Red Hat AI Inference Server 3.3.6 (Spyre)
    • Red Hat AI Inference Server 3.3 registry.redhat.io/rhaiis/vllm-spyre-rhel9

Vendor assessments

Red Hat

Red Hat rating: Important. Red Hat's page for this CVE →

ProductStatusPlan or fix
Red Hat AI Inference ServerAffectedNo fix planned: Will not fix
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix planned: Will not fix
Red Hat OpenShift AI (RHOAI)AffectedNo fix yet
Red Hat AI Inference Server 3.2Fixed RHSA-2026:61627, RHSA-2026:61629
Red Hat AI Inference Server 3.3Fixed RHSA-2026:60363
Red Hat AI Inference Server 3.4Fixed RHSA-2026:69464, RHSA-2026:69466, RHSA-2026:69467, RHSA-2026:69469, RHSA-2026:70965, RHSA-2026:70969, RHSA-2026:70979, RHSA-2026:70995
Red Hat Enterprise Linux AI 3.4Fixed RHSA-2026:76149, RHSA-2026:76150
Not affected: 1 product
  • Red Hat OpenShift AI (RHOAI)

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-55574
  2. 2026-10-03 Alias added: GHSA-rwxx-mrjm-wc2m
  3. 2026-10-06 Fix available: RHSA-2026:76149 · Red Hat
  4. 2026-10-06 Fix available: RHSA-2026:76150 · Red Hat
  5. 2026-10-06 Fix available: Red Hat Enterprise Linux AI 3.4 · Red Hat
  6. 2026-10-07 Affected versions changed · Red Hat

References

Patch 2

Advisory 2

Other 2

  • TI-2024-10229 Remote Code Execution in vllm-project/vllm CVSS 3.0CRITICAL 9.8
  • TI-2024-08404 Remote Code Execution in vllm-project/vllm CVSS 3.1CRITICAL 9.8
  • TI-2026-36017 vLLM: OpenAI auth bypass CVSS 3.1CRITICAL 9.1
  • TI-2026-63056 vLLM before 0.28.0 Denial of Service via negative token ID CVSS 4.0HIGH 8.7
  • TI-2026-04308 Hardcoded trust_remote_code=True in vllm-project/vllm Bypasses User Security Control CVSS 3.0HIGH 8.8
  • TI-2026-39137 vLLM: Remote DoS in vLLM via Invalid Recovered Token Reinjection CVSS 3.1HIGH 7.5
See all 124 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences