Which versions of Xgrammar are affected by CVE-2025-57809?

Organizations using the grammar. This issue has been resolved in face notable risk from CVE-2025-57809 rated CVSS 7.7. Exploitation could compromise the security of affected deployments.. A patch is available.

Is there a public PoC exploit available for CVE-2025-57809?

Yes, a public proof-of-concept exploit is available for CVE-2025-57809. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2025-57809?

Within 7 days: Identify all affected systems running the grammar. This issue has been resolved in and apply vendor patches promptly. Vendor patch is available.

Xgrammar CVE-2025-57809

Q: What is the CVSS score of CVE-2025-57809?

CVE-2025-57809 has a CVSS 4.0 base score of 7.7 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X. EPSS exploitation probability: 0.0%.

HIGH

Uncontrolled Recursion (CWE-674)

2025-08-25 security-advisories@github.com

Information Disclosure Xgrammar Red Hat

7.7

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

7.7 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Red Hat

7.5 HIGH

qualitative

Primary rating from GitHub Advisory.

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Lifecycle Timeline

Analysis Generated

Mar 28, 2026 - 19:08 vuln.today

Patch released

Mar 28, 2026 - 19:08 nvd

Patch available

PoC Detected

Sep 09, 2025 - 18:57 vuln.today

Public exploit code

CVE Published

Aug 25, 2025 - 22:15 nvd

HIGH 7.7

Blast Radius

ecosystem impact

† from your stack dependencies † transitive graph · vuln.today resolves 4-path depth

13 pypi packages depend on xgrammar (3 direct, 10 indirect)

Ecosystem-wide dependent count for version 0.1.21.

DescriptionGitHub Advisory

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.

AnalysisAI

XGrammar is an open-source library for efficient, flexible, and portable structured generation. Rated high severity (CVSS 7.7), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.

Technical ContextAI

This vulnerability is classified under CWE-674. 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. Affected products include: Mlc-Ai Xgrammar. Version information: version 0.1.21.

RemediationAI

A vendor patch is available. Apply the latest security update as soon as possible. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.

Vendor StatusVendor

CVE-2025-57809 vulnerability details – vuln.today

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