xmldom: DocType `name` Injection Bypasses requireWellFormed

Description

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.

Scores

EPSS (exploitation in 30 days)

0.61% · top 51% of all CVEs (6 Nov 2026)

CISA SSVC

Exploitation: poc · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.7.

Weakness

• CWE-91: XML Injection (aka Blind XPath Injection) (opens in a new tab)All about CWE-91 and its CVEs

Affected products

• xmldom · xmldom

  • affected <= 0.6.0

• @xmldom · xmldom

  • affected >= 0.9.0, < 0.9.12
  • affected >= 0.7.0, < 0.8.15

Affected packages

From reviewed advisories of the GitHub Advisory Database.

• npm@xmldom/xmldomGHSA-27p8-2357-5qqv (opens in a new tab)
• npmxmldomGHSA-27p8-2357-5qqv (opens in a new tab)

References (7)

• https://github.com/xmldom/xmldom/security/advisories/GHSA-27p8-2357-5qqv (opens in a new tab)x_refsource_CONFIRMexploit
• https://github.com/xmldom/xmldom/pull/1071 (opens in a new tab)x_refsource_MISC
• https://github.com/xmldom/xmldom/pull/1072 (opens in a new tab)x_refsource_MISC
• https://github.com/xmldom/xmldom/commit/57aec90ac57b4408ae7c5d1746bf2a693b5ed90e (opens in a new tab)x_refsource_MISC
• https://github.com/xmldom/xmldom/commit/85f12eb4d14b44de33216cfb72b50af4d24e9fdd (opens in a new tab)x_refsource_MISC
• https://github.com/xmldom/xmldom/releases/tag/0.8.15 (opens in a new tab)x_refsource_MISC
• https://github.com/xmldom/xmldom/releases/tag/0.9.12 (opens in a new tab)x_refsource_MISC

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisory GHSA-27p8-2357-5qqv (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2026-83608](https://trackcve.app/badge/CVE-2026-83608.svg)](https://trackcve.app/cve/CVE-2026-83608)

Record last updated 4 Sept 2026, 01:56 UTC.