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Fencer Vulns
high 7.5

CVE-2026-25048 json

xgrammar: Multi-layer nesting causes DoS

published 2026-03-05 8 mo ago modified 2026-09-10 1 mo ago also EUVD-2026-9830 , GHSA-7rgv-gqhr-fxg3 , PYSEC-2026-2322

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
1.3%
EPSS 1.3% chance of exploitation in 30 days, percentile 71%
public exploits
0
none known

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.

Patch / fix

  • pypi xgrammar 0.1.32
  • Red Hat Red Hat AI Inference Server 3.2 1774351144, 1774547384, 1775252598
  • Red Hat Red Hat OpenShift AI 2.25 1780069069, 1783998774, 1783998857

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-25048 updated cvss 7.5

xgrammar: xgrammar: Denial of Service via multi-level nested syntax

  • Red Hat AI Inference Server rhaiis/vllm-tpu-rhel9
    affected: workaround, no fix available
  • Red Hat Enterprise Linux AI (RHEL AI) 3 rhelai3/bootc-cuda-rhel9, rhelai3/bootc-aws-cuda-rhel9, rhelai3/bootc-gcp-cuda-rhel9, rhelai3/bootc-azure-cuda-rhel9
    affected: workaround, no fix planned “Will not fix”
  • Red Hat AI Inference Server 3.2 rhaiis 1774351144, rhaiis 1774547384, rhaiis 1775252598
    fixed: vendor fix RHSA-2026:6761
  • Red Hat OpenShift AI 2.25 rhoai/odh-vllm-cuda-rhel9 1783998774, rhoai/odh-vllm-rocm-rhel9 1783998857, rhoai/odh-vllm-gaudi-rhel9 1780069069
    fixed: vendor fix RHSA-2026:42644
  • Red Hat OpenShift AI (RHOAI) rhoai/odh-kserve-agent-rhel9, rhoai/odh-kserve-router-rhel9, rhoai/odh-kserve-controller-rhel9, rhoai/odh-kserve-storage-initializer-rhel9
    not affected: vulnerable code not in execute path
  • Red Hat OpenShift AI 2.25 rhoai/odh-rhel9-operator 1780513840, rhoai/odh-rhel9-operator 1784004914, rhoai/odh-vllm-cpu-rhel9 1780069252, rhoai/odh-vllm-cpu-rhel9 1782397826, rhoai/odh-dashboard-rhel9 1780467029, rhoai/odh-dashboard-rhel9 1782826282, +144 more
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
8 mo ago

Exploit prediction

1.32% chance of exploitation in the next 30 days, higher than 71% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

  • github.com https://github.com/mlc-ai/xgrammar/security/advisories/GHSA-7rgv-gqhr-fxg3 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by version score vector
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
CISA ADP 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 4.0 8.7 CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
NVD 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
OSV 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
pypi xgrammar
<0.1.32
0.1.32

Affected products

  • mlc-ai xgrammar
  • Red Hat Red Hat AI Inference Server 3.2
  • Red Hat Red Hat OpenShift AI 2.25
  • Red Hat Red Hat AI Inference Server
  • Red Hat Red Hat Enterprise Linux AI (RHEL AI) 3
  • Red Hat Red Hat OpenShift AI (RHOAI)

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.

CPEs and fixed versions use Anchore's correction of NVD's data: Added CPE configurations because not yet analyzed by NVD.