CVE-2025-32381 MEDIUM

CVE-2025-32381: Denial of Service by abusing xgrammar unbounded cache in memory

Vendor Mlc-Ai
Product xgrammar
Weakness CWE-770 · Uncontrolled resource consumption
Published April 9, 2025
Last update April 9, 2025

CVSS base score

6.5/10
Attack vector Network
Attack complexity Low
Privileges required Low
User interaction None
Confidentiality None
Integrity None

CVSS vector

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

What the vulnerability does

01Description

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.

Key dates

02Disclosure timeline

April 9, 2025 CVE published
April 9, 2025 Record updated