CVE-2026-83611
xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content
Impact
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 packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| npm | @xmldom/xmldom | >= 0.7.0, <= 0.8.14 | 0.8.15 |
| npm | xmldom | <= 0.6.0 | none recorded |
Weakness classification
References
- NVD record
- CVE.org record
- GitHub advisory
- https://github.com/advisories/GHSA-6h8r-xr42-gp59
- https://github.com/xmldom/xmldom/security/advisories/GHSA-6h8r-xr42-gp59
- https://nvd.nist.gov/vuln/detail/CVE-2026-83611
- https://github.com/xmldom/xmldom/pull/1071
- https://github.com/xmldom/xmldom/pull/1072
- https://github.com/xmldom/xmldom/commit/4430189660b0d380ee9c9ee7550a1358688e8828
- https://github.com/xmldom/xmldom/commit/7b2ec67e1750daadd0bb06c92e875e726544a362
- https://github.com/xmldom/xmldom/releases/tag/0.8.15
- https://github.com/xmldom/xmldom/releases/tag/0.9.12