Vulnerability · Published Apr 2, 2026 · Assigned by GitHub_M
CVE-2026-34601xmldom: XML injection via unsafe CDATA serialization allows attacker-controlled markup insertion
High 7.5
In plain English
A high-severity security flaw in xmldom from xmldom. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | node-xmldom | no fix listed | DEBIAN-CVE-2026-34601 |
| Debian:13 | node-xmldom | no fix listed | DEBIAN-CVE-2026-34601 |
| Debian:14 | node-xmldom | 0.9.9-1 | DEBIAN-CVE-2026-34601 |
| Ubuntu:22.04:LTS | node-xmldom | no fix listed | UBUNTU-CVE-2026-34601 |
| Ubuntu:24.04:LTS | node-xmldom | no fix listed | UBUNTU-CVE-2026-34601 |
| Ubuntu:25.10 | node-xmldom | no fix listed | UBUNTU-CVE-2026-34601 |
| Ubuntu:26.04:LTS | node-xmldom | no fix listed | UBUNTU-CVE-2026-34601 |
| Ubuntu:26.10 | node-xmldom | no fix listed | UBUNTU-CVE-2026-34601 |
| npm | @xmldom/xmldom | 0.9.9 | GHSA-wh4c-j3r5-mjhp |
| npm | @xmldom/xmldom | 0.8.12 | GHSA-wh4c-j3r5-mjhp |
| npm | xmldom | no fix listed | GHSA-wh4c-j3r5-mjhp |
Affected products (as reported)
Weakness: CWE-91 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
References
- https://github.com/xmldom/xmldom/security/advisories/GHSA-wh4c-j3r5-mjhp x_refsource_CONFIRM
- https://github.com/xmldom/xmldom/commit/2b852e836ab86dbbd6cbaf0537f584dd0b5ac184 x_refsource_MISC
- https://github.com/xmldom/xmldom/releases/tag/0.8.12 x_refsource_MISC
- https://github.com/xmldom/xmldom/releases/tag/0.9.9 x_refsource_MISC
- https://access.redhat.com/security/cve/CVE-2026-34601 vdb-entry, x_refsource_REDHAT
- RHBZ#2454595 issue-tracking, x_refsource_REDHAT
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-34601.json x_sadp-csaf-vex