xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module.
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 DOCUMENTTYPENODE 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 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.
Assessment
- CVSS
- 8.7 (v4.0)
- Severity
- High
- EPSS
- 0.61% chance of exploitation in the next 30 days
- Known exploited
- Not listed in CISA KEV
- Exploit availability
- Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
- Published
- 1 September 2026
- Last updated
- 8 September 2026
- Weakness
- CWE-91
- Assigner
- security-advisories@github.com
CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
At the source
References
- https://github.com/xmldom/xmldom/commit/57aec90ac57b4408ae7c5d1746bf2a693b5ed90e
- https://github.com/xmldom/xmldom/commit/85f12eb4d14b44de33216cfb72b50af4d24e9fdd
- https://github.com/xmldom/xmldom/pull/1071
- https://github.com/xmldom/xmldom/pull/1072
- https://github.com/xmldom/xmldom/releases/tag/0.8.15
- https://github.com/xmldom/xmldom/releases/tag/0.9.12
- https://github.com/xmldom/xmldom/security/advisories/GHSA-27p8-2357-5qqv
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