CVE-2026-71488

Name	CVE-2026-71488
Description	league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 0.6.0 until 2.9.0, specially crafted Markdown lines can cause the parser to have quadratic time complexity when converting, because several parsing paths repeatedly rescan growing portions of a line to translate between character positions and byte positions, and the Autolink extension can also copy and validate the remaining line at every URL-like prefix, allowing an attacker who can submit Markdown for conversion to consume disproportionate CPU time with a comparatively small request. This issue is fixed in 2.9.0.
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)	bullseye	1.5.7-2	vulnerable
	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

[trixie] - php-league-commonmark <no-dsa> (Minor issue)
https://github.com/thephpleague/commonmark/security/advisories/GHSA-2q4p-g7hv-5rgv
Fixed by: https://github.com/thephpleague/commonmark/commit/a6ef6cdc308dfa39a34239c35818e75892a0e6a8 (2.9.0)
Fixed by: https://github.com/thephpleague/commonmark/commit/a70979ea0d7d3377bd7127536748454a922bf5eb (2.9.0)
Fixed by: https://github.com/thephpleague/commonmark/commit/c97b02e5e652b992033b93ba5d6182f706343fc6 (2.9.0)