CVE-2026-73491

Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references

Published: Aug 12, 2026Updated: Sep 9, 2026 Sources: CVE List NVDCWE-184

N/ACVSS

NVD MITRE

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: URIs whose scheme is split or prefixed with the HTML5 named whitespace character references &Tab; or &NewLine;. 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.

No summary for this CVE yet.

Weaknesses

CWE-184

Affected Products

flavorjones

oss-projectaka loofah

loofahLibrary

OSS Libraries / rubygems

Exploitability

No known exploits, KEV entries, or remediation guidance available for this vulnerability yet.

References

https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19

github.com

https://github.com/flavorjones/loofah/pull/308

github.com

https://github.com/flavorjones/loofah/releases/tag/v2.25.2

github.com

and 1 more references View all →

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