Microsoft Security Response Center guidance
Vendor revision: Sep 6, 2026See the Microsoft Security Update Guide for the update that applies to your product.
Vulnerability intelligence
CVE-2026-83614 and is rated High severity with a CVSS score of 8.7. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
See the Microsoft Security Update Guide for the update that applies to your product.
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 versions 0.3.0 through 0.6.0, two independent quadratic paths can cause denial of service.
In lib/sax.js, parseElementStartPart repeatedly rescans a malformed tag name to the next > during single-character recovery; in lib/dom.js, normalize() repeatedly removes and appends adjacent text nodes, causing quadratic reindexing and string rebuilding.
The first path is reachable through default DOMParser.parseFromString() processing, while the second is also reachable through a direct normalize() call on a programmatically constructed DOM, and endDocument invokes that normalization after parsing. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.
Source: NVD