High 8.7Published Sep 1, 2026

CVE-2026-83612xmldom: HTML raw-text closing-tag case mismatch causes output amplification

Updated under an hour ago (2026-10-19 11:40 UTC)

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No exploitation reported and no EPSS estimate yet.

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Every CVE for xmldom

Exploited in the last 30 days

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0-beta.1 until 0.9.12, HTML-mode parsing through DOMParser.parseFromString() mishandles a mixed-case closing tag for the script, style, textarea, or title raw-text elements. parseHtmlSpecialContent, selected by isHTMLRawTextElement or isHTMLEscapableRawTextElement, uses a case-sensitive indexOf() and then calls substring() with a missing-close result of negative one, causing unstable parser progression and quadratic output amplification. A small untrusted text/html document can consequently consume disproportionate CPU and memory when parsed and serialized. This issue is fixed in @xmldom/xmldom version 0.9.12.

CVSS: 8.7 HIGH (v4.0, CNA)CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness (CWE): CWE-178, CWE-400
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Sep 1, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

xmldom xmldom xmldom:xmldom (from the name)	from 0.9.0-beta.1, < 0.9.12	CNA record

References

https://github.com/xmldom/xmldom/security/advisories/GHSA-6mj3-qw4j-hgrwx-refsource-confirm
https://github.com/xmldom/xmldom/pull/1071x-refsource-misc
https://github.com/xmldom/xmldom/commit/7ced40c06c28d151e996a97045018c3559ae4707x-refsource-misc
https://github.com/xmldom/xmldom/releases/tag/0.9.12x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.