CVE-2026-83606

Name	CVE-2026-83606
Description	xmldom is a pure JavaScript W3C standard-based (XML DOM Level 2 Core) DOMParser and XMLSerializer module. From 0.9.0-beta.9 until 0.9.11, the processing-instruction production in lib/grammar.js lets the greedy S+ separator and lazy Char*? data group repeatedly repartition a long whitespace tail when the required closing ?> is absent. Both parsePI and parseProcessingInstruction apply the expression to the entire remaining source, causing quadratic backtracking during DOMParser.parseFromString() under default options and allowing a small unauthenticated XML input to stall the Node.js event loop. This issue is fixed in @xmldom/xmldom version 0.9.11.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
node-xmldom (PTS)	bookworm	0.8.6-1	vulnerable
	trixie	0.9.6-1	vulnerable
	forky, sid	0.9.11-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
node-xmldom	source	(unstable)	0.9.11-1

Notes

https://github.com/xmldom/xmldom/security/advisories/GHSA-g53g-w8rj-fmg7
https://github.com/xmldom/xmldom/pull/1039
Fixed by: https://github.com/xmldom/xmldom/commit/73df6b8bdbd86f904b9e8c3ab9c49aa54ef2802e (0.9.11)