CVE-2025-57809: xgrammar — Exploit & Fix

Description

XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.21, XGrammar has an infinite recursion issue in the grammar. This issue has been resolved in version 0.1.21.

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CVSS v3.1 Score

7.5

HIGH

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

Weakness Type (CWE)

CWE-674 CWE-674

Affected Products

Vendor	Product	Versions
mlc-ai	xgrammar	< 0.1.21

References

Advisories & Patches

https://github.com/mlc-ai/xgrammar/commit/b943feacb5a1caf4d39de8ec3bf7c7ce066dcee5 https://github.com/mlc-ai/xgrammar/security/advisories/GHSA-5cmr-4px5-23pc

Exploits

https://github.com/mlc-ai/xgrammar/issues/250

Frequently Asked Questions

What is CVE-2025-57809? +

XGrammar is an open-source library for efficient, flexible, and portable structured generation. Prior to version 0.1.21, XGrammar has an infinite recursion issue in the grammar. This issue has been resolved in version 0.1.21. It has a CVSS v3.1 base score of 7.5 (HIGH).

How severe is CVE-2025-57809? +

CVE-2025-57809 has a CVSS v3.1 score of 7.5 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.

What products are affected by CVE-2025-57809? +

CVE-2025-57809 affects products from mlc-ai, specifically: xgrammar. Check the affected products table above for specific version ranges.

How do I check if I'm vulnerable to CVE-2025-57809? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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