Answer in brief
CVE-2026-73491 records a Low severity vulnerability in Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references. The current sources do not mark it as known exploited. The current feed maps flavorjones/loofah (generic), loofah (rubygems), 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.
Answer in brief
CVE-2026-73491 records a Low severity vulnerability in Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references. The current sources do not mark it as known exploited. The current feed maps flavorjones/loofah (generic), loofah (rubygems), 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.
A CVSS score is not reported in the current record. 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.
The current feed maps flavorjones/loofah (generic), loofah (rubygems), loofah (rubygems). Check affected ranges and fixed versions before updating.
| 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 |
| loofahrubygems | >=2.25.0,<2.25.2 | 2.25.2 |
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 8, 2026
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: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references 	 or 
. CGI.unescapeHTML leaves those references intact, so allowed_uri? reports the URL safe even though a browser decodes and strips the tab or line feed and executes the resulting javascript: URL. 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.
A CVSS score is not reported in the current record. 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.
The current feed maps flavorjones/loofah (generic), loofah (rubygems), loofah (rubygems). Check affected ranges and fixed versions before updating.
| 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 |
| loofahrubygems | >=2.25.0,<2.25.2 | 2.25.2 |
Published upstream
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 8, 2026
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: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references 	 or 
. CGI.unescapeHTML leaves those references intact, so allowed_uri? reports the URL safe even though a browser decodes and strips the tab or line feed and executes the resulting javascript: URL. 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.