CVE-2025-32381

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 v3 6.5 MEDIUM

6.5^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 3.6

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact NONE

Availability Impact HIGH

Scope UNCHANGED

References

Link	Resource
https://github.com/mlc-ai/xgrammar/pull/243	Issue Tracking Patch
https://github.com/mlc-ai/xgrammar/security/advisories/GHSA-389x-67px-mjg3	Vendor Advisory
https://github.com/vllm-project/vllm/pull/16283	Issue Tracking Patch

Configurations

Configuration 1 (hide)

cpe:2.3:a:mlc-ai:xgrammar:*:*:*:*:*:*:*:*

History

No history.

Information

Published : 2025-04-09 16:15

Updated : 2025-09-17 18:14

NVD link : CVE-2025-32381

Mitre link : CVE-2025-32381

CVE.ORG link : CVE-2025-32381

JSON object : View

Products Affected

mlc-ai

xgrammar

CWE

CWE-770

Allocation of Resources Without Limits or Throttling

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