CVE-2025-58446

xgrammar vulnerable to denial of service by huge enum grammar

CVSS 6.9 MEDIUMEPSS 0.5%CWE-770

Vexday Risk Score

13Low

SSVC decision (CISA)

Track

No exploitation signal → monitor

CVSS 6.9EPSS 0.5%KEV nãoPoC —Nuclei —Metasploit —Patch —

Lifecycle

06 Sep 2025Published on NVD

Recommendation: Monitor — no exploitation signal at the moment.

xgrammar is an open-source library for efficient, flexible, and portable structured generation. A grammar optimizer introduced in 0.1.23 processes large grammars (>100k characters) at very low rates, and can be used for DOS of model providers. This issue is fixed in version 0.1.24.

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

Affected products

mlc-ai · xgrammar

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References

https://github.com/mlc-ai/xgrammar/commit/ced69c3ad2f8f61b516cc278a342e7c644383e27 https://github.com/mlc-ai/xgrammar/security/advisories/GHSA-9q5r-wfvf-rr7f