Python Liquid: Infinite loop when parsing malformed `{% case %}` tags (CVE-2026-55865) | HOL Guard CVE

High · CVSS 7.1CVE-2026-55865GHSA-VQ2F-VCC9-J8MV

Python Liquid: Infinite loop when parsing malformed `{% case %}` tags

Answer in brief

CVE-2026-55865 records a High severity (CVSS 7.1) vulnerability in Python Liquid: Infinite loop when parsing malformed `{% case %}` tags. The current sources do not mark it as known exploited. The current feed maps jg-rp/liquid (generic), python-liquid (pip). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

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

Published Jul 9, 2026Updated Jul 14, 2026Source checked Sep 17, 2026First seen by HOL Jun 19, 2026Material review Jul 14, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 7.1
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 7.1. 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 jg-rp/liquid (generic), python-liquid (pip). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
jg-rp/liquidgeneric	< 2.2.1	Not reported
python-liquidpip	<2.2.1	2.2.1

Recommended response

Check inventory. Check lockfiles and deployed manifests for jg-rp/liquid, python-liquid.
Review the reported fix. Update python-liquid to 2.2.1 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jul 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Jul 14, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jun 19, 2026

Sources and claim methodology

Upstream source description

Python Liquid is a Python engine for the Liquid template language. Prior to 2.2.1, given a malformed {% case %} tag without an associated {% when %} or {% else %} block and no terminating {% endcase %} tag, Python Liquid hangs in an infinite loop at parse time because liquid.TokenStream.eof did not give the EOF token matching kind and value fields, allowing malicious template authors to craft templates for a denial of service attack. This issue is fixed in version 2.2.1.

Quoted source text, attributed separately from HOL analysis.