CVE-2026-83614 xmldom: Quadratic-time parsing via the malformed-input recovery path — `parseElementStartPart` re-scan and `normalize()` adjacent-text merge

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 versions 0.3.0 through 0.6.0, two independent quadratic paths can cause denial of service. In lib/sax.js, parseElementStartPart...