> CVE-2026-73556 [MEDIUM]

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PUBLISHED
2026-08-13 15:20
MODIFIED
2026-08-13 15:20
CVSS_SCORE V3
5.3
EPSS (Prob. Exploit)
0.52%
Top 56.9%
DATA SOURCES:
NVD đź”— 2026-08-13 RED HAT đź”— 2026-08-16 CWE MITRE đź”— 2026-11-01 FIRST EPSS đź”— 2026-10-25 OSV đź”— 2026-08-20

> DESCRIPTION

vLLM is an inference and serving engine for large language models. Prior to 0.26.0, the structured_outputs.regex parameter in vllm/v1/structured_output/backend_lm_format_enforcer.py is passed to lmformatenforcer.RegexParser without compile_regex_with_timeout or validation in validate_structured_output_request_lm_format_enforcer, allowing an unauthenticated /v1/completions request against the lm-format-enforcer backend to consume a CPU core and stall the structured-output engine path with a catastrophic regular expression. This issue is fixed in version 0.26.0.

> AFFECTED_PRODUCTS

ℹ️ Aucun produit affecté n'a encore été publié par NVD pour cette CVE.

> CVSS V3 METRICS

CVSS_VECTOR
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
EXPLOITABILITY
3.9
IMPACT
1.4

> MÉTRIQUES CVSS DÉTAILLÉES

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Métrique Valeur Interprétation
AV (Vecteur d'Attaque)
Attack Vector
Network (N)
Exploit possible à distance via réseau (HTTP, API, etc.)
AC (Complexité d'Attaque)
Attack Complexity
Low (L)
Peu de conditions requises pour exploiter
PR (Privilèges Requis)
Privileges Required
None (N)
Aucune authentification requise
UI (Interaction Utilisateur)
User Interaction
None (N)
Aucune interaction utilisateur nécessaire
S (Périmètre)
Scope
Unchanged (U)
Impact reste dans le périmètre du composant compromis
C (Impact Confidentialité)
Confidentiality Impact
None (N)
Aucune divulgation d'informations
I (Impact Intégrité)
Integrity Impact
None (N)
Aucune modification de données possible
A (Impact Disponibilité)
Availability Impact
Low (L)
Interruption partielle du service possible

> RÉSUMÉ DES IMPACTS

Confidentialité
None
Aucune divulgation d'informations
Intégrité
None
Aucune modification de données possible
Disponibilité
Low
Interruption partielle du service possible

> WEAKNESSES

CWE-400 CWE-1333

> CWE DETAILED DESCRIPTIONS

CWE-400: Uncontrolled Resource Consumption - The product does not properly control the allocation and maintenance of a limited resource. | CWE-1333: Inefficient Regular Expression Complexity - The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.

> RED HAT SECURITY ADVISORIES

Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (rocm)
Red Hat AI Inference 3.4.5 (rocm) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (cuda)
Red Hat AI Inference 3.4.5 (cuda) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (cpu)
Red Hat AI Inference 3.4.5 (cpu) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (spyre)
Red Hat AI Inference 3.4.5 (spyre) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (rocm)
Red Hat AI Inference 3.4.5 (rocm) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (cuda)
Red Hat AI Inference 3.4.5 (cuda) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (spyre)
Red Hat AI Inference 3.4.5 (spyre) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.4.5 (cpu)
Red Hat AI Inference 3.4.5 (cpu) is now available.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.4.5 security update
Updated Red Hat Enterprise Linux AI 3.4.5 container images are now available.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.4.5 security update
Updated Red Hat Enterprise Linux AI 3.4.5 container disk images are now available.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.3.7 security update
Updated Red Hat Enterprise Linux AI 3.3.7 container disk images are now available.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.3.7 security update
Updated Red Hat Enterprise Linux AI 3.3.7 container images are now available.
Red Hat Security Advisory: Red Hat AI Inference Tech Preview 3.5.2 (Gaudi)
Red Hat AI Inference Tech Preview 3.5.2 (Gaudi) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.5.2 (ROCm)
Red Hat AI Inference 3.5.2 (ROCm) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.5.2 (cpu)
Red Hat AI Inference 3.5.2 (cpu) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.5.2 (spyre)
Red Hat AI Inference 3.5.2 (spyre) is now available.
Red Hat Security Advisory: Red Hat AI Inference 3.5.2 (cuda)
Red Hat AI Inference 3.5.2 (cuda) is now available.
Red Hat Security Advisory: RHOAI 3.4.5 - Red Hat OpenShift AI
Updated images are now available for Red Hat OpenShift AI.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.5.2 enhancement update
Updated Red Hat Enterprise Linux AI 3.5.2 container images are now available.
Red Hat Security Advisory: Red Hat Enterprise Linux AI 3.5.2 enhancement update
Updated Red Hat Enterprise Linux AI 3.5.2 container disk images are now available.

> RED HAT SEVERITY ASSESSMENT

THREAT SEVERITY
Important

> OSV (GOOGLE OPEN SOURCE VULNERABILITIES)

vLLM: ReDoS via structured_outputs.regex in the lm-format-enforcer backend (no compile timeout) — missed sibling of CVE-2026-55574

AFFECTED PACKAGES:
Unknown / Unknown
98 versions affected
ALIASES:
GHSA-48jh-3gj7-fg8v

> HISTORIQUE DES MODIFICATIONS

Première apparition
13/08/2026 15:20
Source: NVD
đź“Š ENRICHISSEMENT 01/09/2026 06:02
CWE
Champ modifié: Description CWE
Ancienne valeur:
N/A
Nouvelle valeur:
CWE-400: Uncontrolled Resource Consumption - The product does not properly control the allocation and maintenance of a limited resource. | CWE-1333: Inefficient Regular Expression Complexity - The pro...
đź“Š ENRICHISSEMENT 16/08/2026 05:01
REDHAT
Champ modifié: Sévérité Red Hat
Ancienne valeur:
N/A
Nouvelle valeur:
{ "threat_severity": "Important", "severity_scale": null }
đź“Š ENRICHISSEMENT 16/08/2026 05:01
REDHAT
Champ modifié: Red Hat
Ancienne valeur:
Non
Nouvelle valeur:
Oui
Total des modifications: 3 Dernière mise à jour: 2 months ago

> REFERENCES

https://github.com/vllm-project/vllm/commit/c9a788eedc412acceaa5112e0d44624b4984...
https://github.com/vllm-project/vllm/pull/47595
https://github.com/vllm-project/vllm/releases/tag/v0.26.0
https://github.com/vllm-project/vllm/security/advisories/GHSA-48jh-3gj7-fg8v
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