XGrammar affected by Denial of Service by infinite recursion grammars (CVE-2025-57809) | HOL Guard CVE

High · CVSS 7.5CVE-2025-57809GHSA-5CMR-4PX5-23PC

XGrammar affected by Denial of Service by infinite recursion grammars

Answer in brief

CVE-2025-57809 records a High severity (CVSS 7.5) vulnerability in XGrammar affected by Denial of Service by infinite recursion grammars. The current sources do not mark it as known exploited. The current feed maps xgrammar (pypi). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Aug 25, 2025Updated Sep 10, 2026Source checked Sep 10, 2026First seen by HOL Aug 8, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.5
Exploitation: Not marked as known exploited
Affected software: 1 mapped package or product
Fix availability: Available

Why this deserves its current priority

CVSS is 7.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps xgrammar (pypi). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
xgrammarpypi	>=0 <0.1.21	0.1.21

Recommended response

Check inventory. Check lockfiles and deployed manifests for xgrammar.
Review the reported fix. Update xgrammar to 0.1.21 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 25, 2025
Evidence: source:osv:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:osv:source_dates:source-dates:record
First seen by HOL
Aug 8, 2026

Sources and claim methodology

Upstream source description

### Summary This issue: http://github.com/mlc-ai/xgrammar/issues/250 should have it's own security advisory. Since several tools accept and pass user supplied grammars to xgrammar, and it is so easy to trigger it seems like a High.

Quoted source text, attributed separately from HOL analysis.