CVE-2026-83617
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.11 until 0.9.12, the requireWellFormed: true element and attribute name checks use the anchored QName_exact expression produced by reg() in lib/grammar.js, which inherits the multiline flag. A name with a valid first line followed by U+000A, U+000D, U+2028, or U+2029 and breakout markup therefore passes validation and is emitted verbatim in element start and end tags or attribute names. This bypasses the strict-serialization checks introduced for the earlier element-name and attribute-name injection advisories, while the default serialization path remains outside the strict guarantee. 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-2026-83616 — xmldom: Processing Instruction Target Injection Bypasses requireWellFormed
- CVE-2026-83609 — xmldom: Creation-time XML Name/QName validation is bypassable via an embedded line terminator, allowing injection on the default serialization path
- 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