Bug 2558181

Summary:	CVE-2026-103261 python-flit: tornado: Denial of Service (DoS) via unbounded query string parsing [fedora-all]
Product:	[Fedora] Fedora	Reporter:	Vipul Nair <vinair>
Component:	python-flit	Assignee:	Maxwell G <maxwell>
Status:	NEW ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	rawhide	CC:	epel-packagers-sig, maxwell, michel, python-packagers-sig
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["0368210f-d6d8-4d7a-9cf9-b3ca634a8486"]}
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2544529

Description Vipul Nair 2026-10-21 10:09:51 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.

Tornado before 6.5.9 fails to limit the number of query string fields in HTTPServerRequest.__init__, allowing remote attackers to cause event-loop stalling by sending requests with thousands of query parameters. Attackers can send unauthenticated GET requests with unbounded query-string field counts to degrade response times for all clients sharing the same IOLoop.