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, Document.createEntityReference(name) accepts an invalid name and the ENTITY_REFERENCE_NODE serializer emits the resulting nodeName directly in &name; form. Directly serializing the node or fragment with XMLSerializer.serializeToString() and requireWellFormed: true can therefore break the entity-reference boundary and produce attacker-controlled XML markup when reparsed. The parser does not ordinarily create these nodes, and element-child insertion is rejected, so exploitation requires an application to create and directly serialize an EntityReference. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
https://github.com/xmldom/xmldom/security/advisories/GHSA-6gmq-8vp8-gcm6
https://github.com/xmldom/xmldom/releases/tag/0.9.12
https://github.com/xmldom/xmldom/releases/tag/0.8.15
https://github.com/xmldom/xmldom/pull/1072
https://github.com/xmldom/xmldom/pull/1071
https://github.com/xmldom/xmldom/commit/6c3fb5ffeafe7901ec928ce9010988dd716c94a0
https://github.com/xmldom/xmldom/commit/4664386e4f4d99d17b416a151dbe8323e245284b
Published: 2026-09-01
Updated: 2026-09-01
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:N/C:P/I:P/A:P
Severity: High
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 6.3
Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N
Severity: Medium