{"id":"CVE-2026-116802","state":"PUBLISHED","title":"DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode","description":"DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to bypass the SMIL attributeName=href guard when PARSER_MEDIA_TYPE is application/xhtml+xml, because transformCaseFunc does not lowercase attribute names. Attackers can submit SVG with an animate or set element using attributeName=\"href\" and a javascript: entry in values to execute script when users click the sanitized link.","publishedAt":"2026-10-26T23:05:34.457Z","updatedAt":"2026-10-26T23:05:34.457Z","severity":{"score":5.1,"label":"Medium","version":"4.0","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","source":"VulnCheck"},"assigner":"VulnCheck","products":["cure53 DOMPurify"],"affected":[{"vendor":"cure53","product":"DOMPurify","packageURL":"pkg:npm/dompurify","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.4.17","versionType":"semver"},{"version":"3.4.17","status":"unaffected","versionType":"semver"}]}],"references":["https://github.com/cure53/DOMPurify/security/advisories/GHSA-c6gr-qvv4-5v3f","https://www.vulncheck.com/advisories/dompurify-before-3.4.17-xss-via-smil-attributename-guard-bypass-in-xhtml-mode"],"weaknesses":["CWE-79"],"ingestedAt":"2026-10-29T20:10:43.281Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/116xxx/CVE-2026-116802.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-116802","state":"PUBLISHED","datePublished":"2026-10-26T23:05:34.457Z","dateUpdated":"2026-10-26T23:05:34.457Z","assignerShortName":"VulnCheck","assignerOrgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateReserved":"2026-10-26T22:13:13.605Z"},"containers":{"cna":{"title":"DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode","descriptions":[{"lang":"en","value":"DOMPurify before 3.4.17 contains a cross-site scripting vulnerability that allows attackers to bypass the SMIL attributeName=href guard when PARSER_MEDIA_TYPE is application/xhtml+xml, because transformCaseFunc does not lowercase attribute names. Attackers can submit SVG with an animate or set element using attributeName=\"href\" and a javascript: entry in values to execute script when users click the sanitized link."}],"affected":[{"vendor":"cure53","product":"DOMPurify","packageURL":"pkg:npm/dompurify","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"3.4.17","versionType":"semver"},{"version":"3.4.17","status":"unaffected","versionType":"semver"}]}],"references":[{"url":"https://github.com/cure53/DOMPurify/security/advisories/GHSA-c6gr-qvv4-5v3f","tags":["vendor-advisory"],"name":"GitHub Security Advisory (GHSA-c6gr-qvv4-5v3f)"},{"url":"https://www.vulncheck.com/advisories/dompurify-before-3.4.17-xss-via-smil-attributename-guard-bypass-in-xhtml-mode","name":"VulnCheck Advisory: DOMPurify before 3.4.17 XSS via SMIL attributeName Guard Bypass in XHTML Mode","tags":["third-party-advisory"]}],"metrics":[{"cvssV4_0":{"Automatable":"NOT_DEFINED","Recovery":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"NETWORK","baseScore":5.1,"baseSeverity":"MEDIUM","exploitMaturity":"NOT_DEFINED","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"NONE","subConfidentialityImpact":"LOW","subIntegrityImpact":"LOW","userInteraction":"ACTIVE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N","version":"4.0","vulnAvailabilityImpact":"NONE","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"NOT_DEFINED"},"format":"CVSS"},{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"NONE","baseScore":6.1,"baseSeverity":"MEDIUM","confidentialityImpact":"LOW","integrityImpact":"LOW","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N","version":"3.1"},"format":"CVSS"}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]}],"providerMetadata":{"shortName":"VulnCheck","orgId":"83251b91-4cc7-4094-a5c7-464a1b83ea10","dateUpdated":"2026-10-26T23:05:34.457Z"},"datePublic":"2026-10-12T00:00:00.000Z","cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:cure53:dompurify:*:*:*:*:*:*:*:*","versionEndExcluding":"3.4.17"}]}]}],"credits":[{"lang":"en","value":"Koukyosyumei","type":"reporter"}],"x_generator":{"engine":"vulncheck-endgame"}}}}}