Bug 2507880

Summary:	CVE-2026-59922 python-mistune: Mistune: Denial of Service via crafted input [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Hardik Vyas <hvyas>
Component:	python-mistune	Assignee:	Miro Hrončok <mhroncok>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	45	CC:	epel-packagers-sig, mhroncok, neil, python-packagers-sig, romain.geissler
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["a41b138c-e0aa-4401-a565-b7b0a801745b"]}
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2498140

Description Hardik Vyas 2026-07-28 06:53:02 UTC

Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

Mistune is a Python Markdown parser with renderers and plugins. Prior to 3.3.0, a run of closed tilde, equals-sign, or caret marker pairs around a character causes quadratic work in src/mistune/plugins/formatting.py when the strikethrough, mark, or insert plugin scans for matching markers from each possible start position, allowing denial of service through CPU exhaustion. This issue is fixed in version 3.3.0.

Comment 1 Aoife Moloney 2026-08-17 15:38:32 UTC

This bug appears to have been reported against 'rawhide' during the Fedora Linux 45 development cycle.
Changing version to 45.