CVE-2026-83609
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0 until 0.9.12, the shared reg() builder in lib/grammar.js compiles the anchored QName_exact validator with the multiline flag, so ^ and $ validate only one line instead of the complete name. createElementNS, createAttributeNS, createDocumentType, and createAttribute consequently accept a malformed XML name whose first line is valid and whose later text injects markup when serialized through either the default path or requireWellFormed: true. The triggering ECMAScript line terminators are U+000A, U+000D, U+2028, and U+2029. This issue is fixed in @xmldom/xmldom version 0.9.12.
Scoring
- Severity
- HIGH
- CVSS base score
- 8.7
- CVSS 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
- EPSS probability
- 0.33%
- CWE
- CWE-91, CWE-625
- Published
- 2026-09-01
- Last modified
- 2026-09-01
Affected products
- xmldom xmldom
- @xmldom xmldom
Weakness type
Related vulnerabilities
- CVE-2026-83618 — xmldom: requireWellFormed DocType publicId/systemId validation is bypassable via an embedded line terminator
- CVE-2026-83617 — xmldom: requireWellFormed element/attribute name validation is bypassable via an embedded line terminator
- CVE-2026-83616 — xmldom: Processing Instruction Target Injection Bypasses requireWellFormed
- CVE-2026-83608 — xmldom: DocType `name` Injection Bypasses requireWellFormed
- CVE-2026-83607 — xmldom: Element name injection via createElement() bypasses requireWellFormed
- CVE-2026-83605 — xmldom: Attribute name injection via setAttribute() bypasses requireWellFormed
- CVE-2026-48590 — Element and Attribute Names Injected Verbatim into XML Output in xml_builder
- CVE-2026-47080 — CDATA Section Breakout via Unsanitised ]]> in xml_builder