CVE-2026-34601
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.47%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 3.1
- 7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
- EPSS
- 0.47% probability · 39th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-91
- Source
- security-advisories@github.com
References
- https://github.com/xmldom/xmldom/commit/2b852e836ab86dbbd6cbaf0537f584dd0b5ac184
- https://github.com/xmldom/xmldom/releases/tag/0.8.12
- https://github.com/xmldom/xmldom/releases/tag/0.9.9
- https://github.com/xmldom/xmldom/security/advisories/GHSA-wh4c-j3r5-mjhp
- https://access.redhat.com/security/cve/CVE-2026-34601
- https://bugzilla.redhat.com/show_bug.cgi?id=2454595
- https://github.com/xmldom/xmldom/security/advisories/GHSA-wh4c-j3r5-mjhp
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34601.json
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.