CVE-2026-25048: xgrammar is an open-source library for efficient, flexible, and portable structured generation

Q: How do I fix CVE-2026-25048?

xgrammar: upgrade to 0.1.32. Exact commands for each OS are on this page.

Q: Is CVE-2026-25048 being exploited?

CVE-2026-25048 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-25048 affect?

CVE-2026-25048 affects xgrammar. Severity is high (CVSS 7.5). 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.

Q: How urgent is CVE-2026-25048?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

This week

HIGH 7.5REMOTEUPGRADE

CVE-2026-25048 is a high-severity flaw (CVSS 7.5) affecting xgrammar. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 this priority

High severity
Public exploit reference
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.2% (top 32%)
CISA exploited list	No
Weakness	CWE-674
Published	2026-03-05
Last modified	2026-07-21

Publisher (CNA): GitHub, Inc. · Vendor: mlc-ai

Last updated 2026-07-21 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-05 16:16 UTCPublished CVE record published
2026-07-21 12:17 UTCUpdated Record last modified

mlc-ai xgrammar UPGRADE

Affected: < 0.1.32

Fixed in: 0.1.32

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy xgrammar || rpm -q xgrammar || xgrammar --version

2. UPGRADE to 0.1.32 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade xgrammar

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade xgrammar

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-25048?

xgrammar: upgrade to 0.1.32. Exact commands for each OS are on this page.

Is CVE-2026-25048 being exploited?

CVE-2026-25048 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-25048 affect?

CVE-2026-25048 affects xgrammar. Severity is high (CVSS 7.5). 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.

How urgent is CVE-2026-25048?

Priority 53/100. High severity; Public exploit reference; Remotely exploitable, no login, no user action

Related CVEs

CVE-2025-58446 HIGH 7.5 DOWNGRADE xgrammar is an open-source library for efficient, flexible, and portable structured generation
CVE-2025-57809 HIGH 7.5 UPGRADE XGrammar is an open-source library for efficient, flexible, and portable structured generation
CVE-2025-32381 MEDIUM 6.5 UPGRADE XGrammar is an open-source library for efficient, flexible, and portable structured generation

References

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