# CVE-2026-83605: xmldom: Attribute name injection via setAttribute() bypasses requireWellFormed

CVE-2026-83605 is fixed in node-xmldom on 1 platform by DEBIAN-CVE-2026-83605 (version 0.9.11-1), released September 2, 2026. It is not reported as exploited. Patch Radar priority: High.

- Web page: https://patchblox.com/security/cve/CVE-2026-83605
- Priority: High
- CVSS: n/a (Important)
- EPSS: 0.0061
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: Sep 1, 2026
- Weakness: XML Injection (aka Blind XPath Injection)
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-83605

## Description

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.14 and 0.9.11, and in xmldom version 0.6.0 and earlier, Element.setAttribute() calls the private _createAttribute(name) path without validating the attribute name, while Document.createAttribute(name) validates against QName. XMLSerializer.serializeToString() emits attribute names verbatim, and requireWellFormed: true did not validate them, so a crafted name can terminate the intended attribute and inject additional attributes, including event handlers, into browser-consumed output; synthesized xmlns:PREFIX declarations expose the same unchecked-name boundary. This issue is fixed in @xmldom/xmldom versions 0.8.14 and 0.9.11; no fixed version is available for xmldom.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | node-xmldom Debian 14 | 0.9.11-1 | [DEBIAN-CVE-2026-83605](https://patchblox.com/security/data/fix/linux/debian-cve-2026-83605.md) | Sep 2, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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