CVE-2026-83619 — xmldom: End-tag Whitespace-Trim Regex ReDoS — quadratic backtracking in the 0.8.x end-tag parser
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.7.0 until 0.8.15, the release-0.8.x parser in lib/sax.js trims c…
Published: 2026-09-01 · CVSS: 8.7 · CVSS 4.0
xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.7.0 until 0.8.15, the release-0.8.x parser in lib/sax.js trims captured end-tag names with the unanchored global expression /[ \t\n\r]+$/g. For an end tag containing a long whitespace run followed by a non-whitespace character, the expression retries from each possible starting position and backtracks quadratically before failing its end anchor. DOMParser.parseFromString() reaches the path under default options, allowing a small unauthenticated XML input to stall the Node.js event loop; the 0.9.x and unscoped npm lines do not contain this expression. This issue is fixed in @xmldom/xmldom version 0.8.15.
Source: CVE Program · Revision 8b16575c39f1e1810c5e863010da073d2d3285e7