CVE-2026-73491

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.

CVSS 4.0

2.3CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

EPSS

0.4% chance of exploitation in the next 30 days; higher than 33% of CVEs (scores of 2026-10-25)

CWE

CWE-184

Published

2026-08-12

Modified

2026-10-24

Record from

the NVD, synced 2026-10-24

Packages (OSV)

References

• https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19
• https://github.com/flavorjones/loofah/pull/308
• https://github.com/flavorjones/loofah/releases/tag/v2.25.2
• https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv

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