CVE-2026-73491: low-severity vulnerability in flavorjones loofah
Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references
Published · Updated
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8Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 2.3epss 0.4%
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/AV:N/AC:H/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N
Affected products
flavorjones · loofahRelated CVEs — flavorjones loofah
In the same product, most dangerous first.
CVE-2022-23514HIGHInefficient Regular Expression Complexity in LoofahEPSS 1.8%CVE-2022-23516HIGHUncontrolled Recursion in LoofahEPSS 1.2%CVE-2022-23515MEDIUMImproper neutralization of data URIs may allow XSS in LoofahEPSS 0.9%CVE-2026-73492LOWLoofah `allowed_uri?` does not detect `javascript:` URIs split by numeric character references without semicolonsEPSS 0.4%CVE-2026-73490MEDIUMLoofah: SVG `href` attribute bypasses local-reference restrictionEPSS 0.3%