{"id":"CVE-2026-83607","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-83607","generatedAt":"2026-10-28T03:40:46.413Z","title":"The requireWellFormed: true path did not validate the element qualified name or synthesized xmlns:PREFIX declaration, so attacker-controlled tag names could inject attributes, elements, or processing instructions into serialized XML or HTML and could…","description":"xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.14 and 0.9.11, and in xmldom version 0.6.0 and earlier, Document.createElement(tagName) stores an unvalidated element name and XMLSerializer.serializeToString() emits that name verbatim. The requireWellFormed: true path did not validate the element qualified name or synthesized xmlns:PREFIX declaration, so attacker-controlled tag names could inject attributes, elements, or processing instructions into serialized XML or HTML and could cause cross-site scripting when browser-consumed. The unchecked values violate the XML QName constraint, and default serialization and creation-time createElement() behavior remain permissive. This issue is fixed in @xmldom/xmldom versions 0.8.14 and 0.9.11; no fixed version is available for xmldom.","published":"2026-09-01T15:17:39.000Z","lastModified":"2026-09-08T21:11:32.000Z","status":"Deferred","sourceIdentifier":"security-advisories@github.com","cvss":{"version":"4.0","score":8.7,"severity":"HIGH","vector":"CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M"},"cwe":["CWE-91"],"affected":[],"epss":{"score":0.00612,"percentile":0.49079,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (0.61%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://github.com/xmldom/xmldom/commit/cba1321218b069182695813fa7565653708e172e","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/commit/d8212e632507eaf1d9f609657dd4c56abeb12d44","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/pull/1043","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/pull/1050","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/releases/tag/0.8.14","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/releases/tag/0.9.11","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/security/advisories/GHSA-w2rr-34g9-rvrj","source":"security-advisories@github.com"},{"url":"https://github.com/xmldom/xmldom/security/advisories/GHSA-w2rr-34g9-rvrj","source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-83607","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}