# CVE-2026-83611

## Summary

- **CVE ID:** CVE-2026-83611
- **Severity:** MEDIUM
- **CVSS Score:** 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N)
- **CWE:** CWE-1286
- **Published:** Sep 1, 2026
- **Last Modified:** Sep 1, 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, DOMParser.parseFromString() can silently accept an end tag such as </a\njunk>, close the element, and discard the trailing content. On 0.9.x, the lib/sax.js end-tag validator inherits the multiline flag from reg(), allowing the first line to satisfy the anchored XML ETag production; older lines have no equivalent residue validation. This parser differential can bypass a parse-before-trust well-formedness gate, although it does not inject the discarded content; onError on 0.9.x and errorHandler on 0.8.x are the relevant reporting interfaces. 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-6h8r-xr42-gp59)
- [CNA](https://github.com/xmldom/xmldom/pull/1071)
- [CNA](https://github.com/xmldom/xmldom/pull/1072)
- [CNA](https://github.com/xmldom/xmldom/commit/4430189660b0d380ee9c9ee7550a1358688e8828)
- [CNA](https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362)
- [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:** 28.4

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