High severity · published Apr 2, 2026
CVE-2026-34601
xmldom: XML injection via unsafe CDATA serialization allows attacker-controlled markup insertion
7.5
CVSS
0.5%
EPSS
No
On KEV
Description
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) `DOMParser` and `XMLSerializer` module. In xmldom versions 0.6.0 and prior and @xmldom/xmldom prior to versions 0.8.12 and 0.9.9, xmldom/xmldom allows attacker-controlled strings containing the CDATA terminator ]]> to be inserted into a CDATASection node. During serialization, XMLSerializer emitted the CDATA content verbatim without rejecting or safely splitting the terminator. As a result, data intended to remain text-only became active XML markup in the serialized output, enabling XML structure injection and downstream business-logic manipulation. This issue has been patched in xmldom version 0.6.0 and @xmldom/xmldom versions 0.8.12 and 0.9.9.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
High
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 41% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
XM
xmldom · xmldom
xmldom <= 0.6.0; @xmldom/xmldom < 0.8.12; @xmldom/xmldom >= 0.9.0, < 0.9.9 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-34601
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-34601
github.com
https://github.com/xmldom/xmldom/commit/2b852e836ab86dbbd6cbaf0537f584dd0b5ac184
github.com
https://github.com/xmldom/xmldom/releases/tag/0.8.12
github.com
https://github.com/xmldom/xmldom/releases/tag/0.9.9
github.com
https://github.com/xmldom/xmldom/security/advisories/GHSA-wh4c-j3r5-mjhp
access.redhat.com
https://access.redhat.com/security/cve/CVE-2026-34601
bugzilla.redhat.com
https://bugzilla.redhat.com/show_bug.cgi?id=2454595
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