CVE-2026-83608
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, the DOCUMENT_TYPE_NODE branch in lib/dom.js validates publicId, systemId, and internalSubset under requireWellFormed: true but emits DocumentType.name verbatim. A name containing > or whitespace can terminate the <!DOCTYPE ...> declaration and inject sibling markup; the value can be supplied through createDocumentType() on the 0.8.x and unscoped lines or through a direct DocumentType.name property write on every affected line. The default path and legacy creation-time behavior remain permissive, while the vulnerable strict path fails to enforce an XML Name. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
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
- 0.35%
- CWE
- CWE-91
- Published
- 2026-09-01
- Last modified
- 2026-09-04
Affected products
- xmldom xmldom
- @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-2026-83609 — xmldom: Creation-time XML Name/QName validation is bypassable via an embedded line terminator, allowing injection on the default serialization path
- 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