{"id":"CVE-2026-73491","state":"PUBLISHED","title":"Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references","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.","publishedAt":"2026-08-12T20:59:18.589Z","updatedAt":"2026-08-13T13:49:22.724Z","severity":{"score":2.3,"label":"Low","version":"4.0","vector":"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","source":"GitHub_M"},"assigner":"GitHub_M","products":["flavorjones loofah"],"affected":[{"vendor":"flavorjones","product":"loofah","versions":[{"version":">= 2.25.0, < 2.25.2","status":"affected"}]}],"references":["https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv","https://github.com/flavorjones/loofah/pull/308","https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19","https://github.com/flavorjones/loofah/releases/tag/v2.25.2"],"weaknesses":["CWE-184"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/73xxx/CVE-2026-73491.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-73491","state":"PUBLISHED","datePublished":"2026-08-12T20:59:18.589Z","dateUpdated":"2026-08-13T13:49:22.724Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-08-12T19:00:33.735Z"},"containers":{"cna":{"title":"Loofah `allowed_uri?` does not detect `javascript:` URIs split by named whitespace character references","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"flavorjones","product":"loofah","versions":[{"version":">= 2.25.0, < 2.25.2","status":"affected"}]}],"references":[{"url":"https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv","name":"https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/flavorjones/loofah/pull/308","name":"https://github.com/flavorjones/loofah/pull/308","tags":["x_refsource_MISC"]},{"url":"https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19","name":"https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19","tags":["x_refsource_MISC"]},{"url":"https://github.com/flavorjones/loofah/releases/tag/v2.25.2","name":"https://github.com/flavorjones/loofah/releases/tag/v2.25.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV4_0":{"attackVector":"NETWORK","attackComplexity":"HIGH","attackRequirements":"NONE","privilegesRequired":"LOW","userInteraction":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","subAvailabilityImpact":"NONE","baseScore":2.3,"baseSeverity":"LOW","vectorString":"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","version":"4.0"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-184","lang":"en","description":"CWE-184: Incomplete List of Disallowed Inputs","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-08-12T20:59:18.589Z"},"source":{"advisory":"GHSA-8whx-365g-h9vv","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-08-13T13:49:09.263231Z","id":"CVE-2026-73491","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-08-13T13:49:22.724Z"}}]}}}