CVE-2026-73491

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{"affected": [{"affectedData": [{"product": "loofah", "vendor": "flavorjones", "versions": [{"status": "affected", "version": ">= 2.25.0, < 2.25.2"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}, {"lang": "es", "value": "Loofah es una biblioteca general para manipular y transformar documentos y fragmentos HTML/XML, construida sobre Nokogiri. Desde la versi\u00f3n 2.25.0 hasta la 2.25.2, Loofah::HTML5::Scrub.allowed_uri? no rechaza las URIs javascript_disabled: cuyo esquema est\u00e1 dividido o prefijado con las referencias de caracteres de espacio en blanco con nombre de HTML5 y Tab; o y NewLine;. CGI.unescapeHTML deja esas referencias intactas, por lo que allowed_uri? informa que la URL es segura aunque un navegador decodifica y elimina la tabulaci\u00f3n o el salto de l\u00ednea y ejecuta la URL javascript_disabled: resultante. Este problema afecta solo a los llamadores que pasan cadenas codificadas en HTML directamente a allowed_uri?; la ruta sanitize() predeterminada de Loofah no se ve afectada. Este problema est\u00e1 solucionado en la versi\u00f3n 2.25.2."}], "id": "CVE-2026-73491", "lastModified": "2026-10-24T15:10:00.190", "metrics": {"cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "HIGH", "attackRequirements": "NONE", "attackVector": "NETWORK", "availabilityRequirement": "NOT_DEFINED", "baseScore": 2.3, "baseSeverity": "LOW", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "LOW", "subIntegrityImpact": "LOW", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X", "version": "4.0", "vulnAvailabilityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "NOT_DEFINED"}, "source": "security-advisories@github.com", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-73491", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "partial"}], "role": "CISA Coordinator", "timestamp": "2026-08-13T13:49:09.263231Z", "version": "2.0.3"}}]}, "published": "2026-08-12T21:17:42.273", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19"}, {"source": "security-advisories@github.com", "url": "https://github.com/flavorjones/loofah/pull/308"}, {"source": "security-advisories@github.com", "url": "https://github.com/flavorjones/loofah/releases/tag/v2.25.2"}, {"source": "security-advisories@github.com", "url": "https://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Awaiting Analysis", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-184"}], "source": "security-advisories@github.com", "type": "Secondary"}]}

{"bugzilla": {"description": "loofah: Loofah: Cross-Site Scripting via malformed `javascript:` URI parsing", "id": "2514986", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2514986"}, "csaw": false, "cvss3": {"cvss3_base_score": "3.7", "cvss3_scoring_vector": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:U/C:L/I:L/A:N", "status": "draft"}, "cwe": "CWE-1289", "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 &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.", "A flaw was found in Loofah. The `Loofah::HTML5::Scrub.allowed_uri?` function fails to properly detect `javascript:` Uniform Resource Identifiers (URIs) when their scheme is split or prefixed with HTML5 named whitespace character references, such as `&Tab;` or `&NewLine;`. This vulnerability allows a remote attacker to craft a malicious URI that, when processed by affected callers, is incorrectly deemed safe. Consequently, a web browser will decode and execute the embedded JavaScript code, leading to Cross-Site Scripting (XSS) and potential arbitrary code execution in the user's browser context."], "name": "CVE-2026-73491", "public_date": "2026-08-12T20:59:18Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-73491\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-73491\nhttps://github.com/flavorjones/loofah/commit/5e91af861e3cdab47b91dd0b81f3afdfd13a5e19\nhttps://github.com/flavorjones/loofah/pull/308\nhttps://github.com/flavorjones/loofah/releases/tag/v2.25.2\nhttps://github.com/flavorjones/loofah/security/advisories/GHSA-8whx-365g-h9vv"], "threat_severity": "Low"}

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