CVE-2026-115349

Name	CVE-2026-115349
Description	Mistune from 3.0.0 before 3.3.0 contains an algorithmic complexity denial of service vulnerability in the parse_link_text function in src/mistune/helpers.py. Attackers can submit markdown with deeply nested square brackets triggering quadratic parsing time, exhausting server CPU with small crafted requests.
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
mistune (PTS)	bookworm	2.0.4-1	vulnerable
	trixie	3.1.3-1	vulnerable
	forky	3.1.4-1	vulnerable
	sid	3.4.0-1	fixed

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

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
mistune	source	(unstable)	3.3.4-1

https://github.com/lepture/mistune/security/advisories/GHSA-3q64-rw38-243v