{"id":"CVE-2026-73491","summary":"Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references","details":"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.","aliases":["GHSA-8whx-365g-h9vv"],"modified":"2026-08-15T11:31:16.372183407Z","published":"2026-08-12T20:59:18.589Z","related":["CGA-j69j-2mw5-vqqj"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73491.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-184"]},"references":[{"type":"WEB","url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/73xxx/CVE-2026-73491.json"},{"type":"ADVISORY","url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-73491"},{"type":"FIX","url":"https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19"},{"type":"FIX","url":"https://github.com/flavorjones/loofah/pull/308"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/flavorjones/loofah","events":[{"introduced":"e65bdddfd3381f3a131be7e137d89bb3959c072b"},{"fixed":"5e91af861e3cdab47b91dd0b81f3afdfd13a5e19"},{"fixed":"2706d7e858426ba856d9711b0e761b2fee7986c4"}],"database_specific":{"extracted_events":[{"introduced":"2.25.0"},{"fixed":"2.25.2"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["v2.25.1","v2.25.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-73491.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}