CVE-2026-86432

Name	CVE-2026-86432
Description	commonmark versions from 2.0.0 before 2.8.4 contain a denial of service vulnerability in XmlRenderer that emits depth-proportional indentation for every XML tag. Attackers can provide deeply nested Markdown or AST structures to cause quadratic memory consumption and output amplification, exhausting server resources.
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
php-league-commonmark (PTS)	bookworm	2.3.9-1+deb12u1	vulnerable
	trixie	2.7.0-1+deb13u1	vulnerable
	forky, sid	2.10.0-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
php-league-commonmark	source	(unstable)	2.9.0-1

Notes

https://github.com/thephpleague/commonmark/security/advisories/GHSA-mj63-m3rc-8ppr
Fixed by: https://github.com/thephpleague/commonmark/commit/b5ac8c3947ca81844e85a09c7e0a5b4148bde2e1 (2.9.0)