Description
On the @xmldom/xmldom 0.8.x line, parsing an XML end tag whose name is followed by a long run of whitespace and then a non-whitespace character triggers quadratic-time regular-expression backtracking (ReDoS), so a single small crafted end tag stalls the Node.js event loop. It is reachable from DOMParser.parseFromString under default options, unauthenticated, before any validity check — an availability-only denial of service. The `0.9.
Recommendation
Update the @xmldom/xmldom package to the latest compatible version. Followings are version details:
- Affected version(s): >= 0.7.0, <= 0.8.14
- Patched version(s): 0.8.15
References
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- xmldom PI grammar regex ReDoS: quadratic backtracking on unterminated processing instructions - CVE-2026-83606
- xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content - CVE-2026-83611
- LiquidJS Vulnerable to ReDoS via Quadratic Backtracking in `strip_html` Filter Regex - CVE-2026-45617
- xmldom: Parser silently accepts a not-well-formed end tag whose name is followed by a line break and trailing content - xmldom - CVE-2026-83611
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See something that needs correcting? Let us knowUpdated September 08, 2026