CVE-2026-83618: high-severity vulnerability in @xmldom xmldom
xmldom: requireWellFormed DocType publicId/systemId validation is bypassable via an embedded line terminator
Published · Updated
E-mail alert when it lands in KEV, gets a public PoC or its score goes up.
21Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackcvss 8.7epss 0.6%
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.10 until 0.9.12, the requireWellFormed: true serializer validates DocumentType.publicId and DocumentType.systemId with PubidLiteral_match and SystemLiteral_match expressions produced by reg() in lib/grammar.js, which inherit the multiline flag. A complete valid literal on the first line can therefore satisfy the matcher while U+000A, U+000D, U+2028, or U+2029 and breakout markup remain in the emitted <!DOCTYPE ...> declaration. This bypasses the strict-serialization mitigation for the earlier DocumentType injection advisory; creation and direct property assignment remain unvalidated by design. This issue is fixed in @xmldom/xmldom version 0.9.12.
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
Related CVEs — @xmldom xmldom
In the same product, most dangerous first.
CVE-2022-39353CRITICALxmldom allows multiple root nodes in a DOMEPSS 1.6%CVE-2021-32796MEDIUMMisinterpretation of malicious XML input in xmldomEPSS 1.4%CVE-2021-21366MEDIUMMisinterpretation of malicious XML inputEPSS 1.3%CVE-2026-41673HIGHxmldom: Denial of service via uncontrolled recursion in XML serializationEPSS 0.6%CVE-2026-83611MEDIUMxmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing contentEPSS 0.6%CVE-2026-83616HIGHxmldom: Processing Instruction Target Injection Bypasses requireWellFormedEPSS 0.6%