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TI-2026-20232 Aliases CVE-2026-25048GHSA-7rgv-gqhr-fxg3

xgrammar: Multi-layer nesting causes DoS

Priority MEDIUM 46CWE-674Published · 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: 2 fixed, 2 without a fix

Attack profile from CVSS 4.0 · CNA. Fix status from CNA, GitHub and Red Hat. Impact type from CWE-674.

Summary

xgrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.32, the multi-level nested syntax caused a segmentation fault (core dumped). This issue has been patched in version 0.1.32.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.01321 71st percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Partial xgrammar (mlc-ai): 0.1.32xgrammar (PyPI): 0.1.32Red Hat: 5 advisoriesRed Hat: 2 fixed, 2 without a fix

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
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
mlc-aixgrammarbefore 0.1.320.1.32Patch availableCNA
—xgrammar (PyPI)before 0.1.320.1.32Patch availableGHSA-7rgv-gqhr-fxg3
  • xgrammar Vendormlc-ai Affected before 0.1.32 Fixed in 0.1.32 Patch available CNA
  • xgrammar (PyPI) Vendor— Affected before 0.1.32 Fixed in 0.1.32 Patch available GHSA-7rgv-gqhr-fxg3

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:mlc-ai:xgrammar:*:*:*:*:*:*:*:*before 0.1.32Vulnerablemlc-ai
  • cpe:2.3:a:mlc-ai:xgrammar:*:*:*:*:*:*:*:* Versions before 0.1.32 Vulnerable ·mlc-ai

Remediation

  • Fix · CNA xgrammar (mlc-ai) Fixed in 0.1.32
  • Fix · GHSA-7rgv-gqhr-fxg3 xgrammar (PyPI) Fixed in 0.1.32 Advisory →

Red Hat 5 advisories

  • RHSA-2026:42644 Released 2026-07-21 · Red Hat rating Important
    RHOAI 2.25.9 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-feature-server-rhel9, registry.redhat.io/rhoai/odh-kserve-storage-initializer-rhel9 +36
  • RHSA-2026:24977 Released 2026-06-10 · Red Hat rating Important
    RHOAI 2.25.7 - Red Hat OpenShift AI
    • Red Hat OpenShift AI 2.25 registry.redhat.io/rhoai/odh-caikit-nlp-rhel9, registry.redhat.io/rhoai/odh-caikit-tgis-serving-rhel9, registry.redhat.io/rhoai/odh-dashboard-rhel9 +34
  • RHSA-2026:6762 Released 2026-04-07 · 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
Show 2 more Red Hat advisories
  • RHSA-2026:6761 Released 2026-04-07 · Red Hat rating Important
    Red Hat AI Inference Server Model Optimization Tools 3.2.2 (CUDA)
    • Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/model-opt-cuda-rhel9
  • RHSA-2026:5809 Released 2026-03-25 · Red Hat rating Important
    Red Hat AI Inference Server 3.2.2 (cuda-ubi9)
    • Red Hat AI Inference Server 3.2 registry.redhat.io/rhaiis/vllm-cuda-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 yet
Red Hat Enterprise Linux AI (RHEL AI) 3AffectedNo fix planned: Will not fix
Red Hat AI Inference Server 3.2Fixed RHSA-2026:5809, RHSA-2026:6761, RHSA-2026:6762
Red Hat OpenShift AI 2.25Fixed RHSA-2026:24977, RHSA-2026:42644
Not affected: 2 products
  • Red Hat OpenShift AI (RHOAI)
  • Red Hat OpenShift AI 2.25

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-25048
  2. 2026-10-03 Alias added: GHSA-7rgv-gqhr-fxg3
  3. 2026-11-06 Fix available: RHSA-2026:42644 · Red Hat

References

Exploit 1

Advisory 1

Other 2

  • TI-2025-36204 xgrammar vulnerable to denial of service by huge enum grammar CVSS 4.0MEDIUM 6.9
  • TI-2025-35692 XGrammar affected by Denial of Service by infinite recursion grammars CVSS 4.0HIGH 7.7
  • TI-2025-23460 Denial of Service by abusing xgrammar unbounded cache in memory CVSS 3.1MEDIUM 6.5

Sources

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