Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons (CVE-2026-73492) | HOL Guard CVE

Low · CVSS 2.3CVE-2026-73492GHSA-5QHF-9PHG-95M2

Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons

Answer in brief

CVE-2026-73492 records a Low severity (CVSS 2.3) vulnerability in Loofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolons. The current sources do not mark it as known exploited. The current feed maps flavorjones/loofah (generic), loofah (rubygems). 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 12, 2026Updated Sep 10, 2026Source checked Sep 28, 2026First seen by HOL Aug 8, 2026Material review Sep 10, 2026

Upstream Advisory

Key facts

Risk: Low · CVSS 2.3
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 2.3. 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 flavorjones/loofah (generic), loofah (rubygems). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
flavorjones/loofahgeneric	>= 2.25.0, < 2.25.2	Not reported
loofahrubygems	>=2.25.0 <2.25.2	2.25.2

Recommended response

Check inventory. Check lockfiles and deployed manifests for flavorjones/loofah, loofah.
Review the reported fix. Update loofah to 2.25.2 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Aug 8, 2026

Sources and claim methodology

Upstream source description

Loofah is a general library for manipulating and transforming HTML/XML documents and fragments, built on top of Nokogiri. From 2.25.0 until 2.25.2, Loofah::HTML5::Scrub.allowed_uri? does not reject javascript: or vbscript: URIs whose scheme is split by semicolon-less numeric character references such as &#58, &#9, &#10, or &#13. CGI.unescapeHTML leaves these references encoded, so allowed_uri? reports the URL safe even though a browser decodes an encoded colon or strips encoded whitespace and executes the resulting URI scheme. This issue affects only callers that pass HTML-encoded strings directly to allowed_uri?; Loofah's default sanitize() path is not affected. This issue is fixed in version 2.25.2.

Quoted source text, attributed separately from HOL analysis.