CVE-2025-32381
Since the cache is unbounded, a system making use of xgrammar can be abused to fill up a host's memory and case a denial of service.
Does this matter?
Lower severity and a low EPSS score (0.50%). Track it; it rarely justifies an emergency change on its own.
Description
XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to 0.1.18, Xgrammar includes a cache for compiled grammars to increase performance with repeated use of the same grammar. This cache is held in memory. Since the cache is unbounded, a system making use of xgrammar can be abused to fill up a host's memory and case a denial of service. For example, sending many small requests to an LLM inference server with unique JSON schemas would eventually cause this denial of service to occur. This vulnerability is fixed in 0.1.18.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
- EPSS
- 0.50% probability · 41th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-770
- Affected
- mlc-ai/xgrammar
- Source
- security-advisories@github.com
References
- https://github.com/mlc-ai/xgrammar/pull/243Issue Tracking, Patch
- https://github.com/mlc-ai/xgrammar/security/advisories/GHSA-389x-67px-mjg3Vendor Advisory
- https://github.com/vllm-project/vllm/pull/16283Issue Tracking, Patch
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.