# CVE-2026-83608

## Summary

- **CVE ID:** CVE-2026-83608
- **Severity:** HIGH
- **CVSS Score:** 8.7 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-91
- **Published:** Sep 1, 2026
- **Last Modified:** Sep 4, 2026

## Description

xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. Prior to @xmldom/xmldom versions 0.8.15 and 0.9.12, and in xmldom version 0.6.0 and earlier, the DOCUMENT_TYPE_NODE branch in lib/dom.js validates publicId, systemId, and internalSubset under requireWellFormed: true but emits DocumentType.name verbatim. A name containing > or whitespace can terminate the <!DOCTYPE ...> declaration and inject sibling markup; the value can be supplied through createDocumentType() on the 0.8.x and unscoped lines or through a direct DocumentType.name property write on every affected line. The default path and legacy creation-time behavior remain permissive, while the vulnerable strict path fails to enforce an XML Name. This issue is fixed in @xmldom/xmldom versions 0.8.15 and 0.9.12; no fixed version is available for xmldom.

## Affected Products

- xmldom — xmldom (<= 0.6.0)
- @xmldom — xmldom (>= 0.9.0, < 0.9.12)
- @xmldom — xmldom (>= 0.7.0, < 0.8.15)

## References

- [CNA](https://github.com/xmldom/xmldom/security/advisories/GHSA-27p8-2357-5qqv)
- [CNA](https://github.com/xmldom/xmldom/pull/1071)
- [CNA](https://github.com/xmldom/xmldom/pull/1072)
- [CNA](https://github.com/xmldom/xmldom/commit/57aec90ac57b4408ae7c5d1746bf2a693b5ed90e)
- [CNA](https://github.com/xmldom/xmldom/commit/85f12eb4d14b44de33216cfb72b50af4d24e9fdd)
- [CNA](https://github.com/xmldom/xmldom/releases/tag/0.8.15)
- [CNA](https://github.com/xmldom/xmldom/releases/tag/0.9.12)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.35%
- **EPSS Percentile:** 28.0

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-11._