Bug 2560071

Summary:	CVE-2026-115348 python-mistune: mistune: Denial of Service via unbalanced brackets in link parser [epel-9]
Product:	[Fedora] Fedora EPEL	Reporter:	Ronit Dey <rdey>
Component:	python-mistune	Assignee:	Neil Hanlon <neil>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	epel9	CC:	epel-packagers-sig, mhroncok, neil, python-packagers-sig, romain.geissler
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["65d3184d-7393-4094-9ed8-3cdb4592492a"]}
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2559376

Description Ronit Dey 2026-10-23 17:19:49 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 from 3.0.0 before 3.3.0 contains an algorithmic complexity vulnerability in the inline link parser's parse_link_text function that allows unauthenticated attackers to exhaust CPU with unbalanced brackets. Attackers can submit Markdown containing many unbalanced '[' or '![' characters, forcing repeated unbounded forward scans and tying up worker processes for minutes.