Bug 2566914

Summary:	CVE-2026-118384 mtools: mtools: Denial of Service via out-of-bounds write in VFAT parsing [fedora-43]
Product:	[Fedora] Fedora	Reporter:	Oleg Sushchenko <osushche>
Component:	mtools	Assignee:	Vojtech Trefny <vtrefny>
Status:	ON_QA ---	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	43	CC:	vtrefny
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["45fd65be-9522-4cef-be37-0052a0bc0453"]}
Fixed In Version:		Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:		Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:
Bug Blocks:	2562560

Description Oleg Sushchenko 2026-11-04 13:46:10 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.

GNU mtools through 4.0.49 has an out-of-bounds write in parse_vses in vfat.c.

Comment 1 Fedora Update System 2026-11-04 14:10:47 UTC

FEDORA-2026-93ccf43a01 (mtools-4.0.50-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-93ccf43a01

Comment 2 Fedora Update System 2026-11-05 16:08:29 UTC

FEDORA-2026-93ccf43a01 has been pushed to the Fedora 43 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-93ccf43a01`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-93ccf43a01

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.