CVE-2026-25048

xgrammar: Multi-layer nesting causes DoS

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.

Affected

mlc-ai · xgrammar

CVSS v4.0 GITHUB

8.7 HIGHCVSS: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

CVSS v4.0 GitHub

8.7 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS v3.1 NVD

7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

1.17% chance of exploitation in the next 30 days, 67th percentile

Published

2026-03-05

Updated

2026-07-21

Proof-of-concept exploits (1)

• advisories/GHSA-7rgv-gqhr-fxg3

Security advisories

• mlc-ai/xgrammar/security/advisories/GHSA-7rgv-gqhr-fxg3
• mlc-ai/xgrammar/releases/tag/v0.1.32

References

• CVE Record
• NVD entry