Bug 2562064

Summary:	CVE-2026-115506 mingw-expat: expat: Denial of Service via delayed entity amplification detection [fedora-43]
Product:	[Fedora] Fedora	Reporter:	Srikanth Balasubramanian <sbalasub>
Component:	mingw-expat	Assignee:	Richard W.M. Jones <rjones>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	high	Docs Contact:
Priority:	high
Version:	43	CC:	manisandro, rjones
Target Milestone:	---	Keywords:	Security, SecurityTracking
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:	{"flaws": ["6ffbdc2a-7c26-43da-ae7a-ebeec118aae3"]}
Fixed In Version:	mingw-expat-2.9.0-1.fc43	Doc Type:	---
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2026-11-09 01:50:49 UTC	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:	2559312

Description Srikanth Balasubramanian 2026-10-27 16:47:13 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.

libexpat through 2.9.0 contains a denial of service vulnerability because billion laughs protection in accountingDiffTolerated() in xmlparse.c detects entity amplification too late. Attackers can supply a moderately sized XML document with a large DTD and nested entity expansions to consume tens of seconds of CPU per parse.

Comment 1 Fedora Update System 2026-10-31 15:13:50 UTC

FEDORA-2026-a83294f5ab (mingw-expat-2.9.0-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-a83294f5ab

Comment 2 Fedora Update System 2026-11-01 03:17:47 UTC

FEDORA-2026-a83294f5ab 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-a83294f5ab`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-a83294f5ab

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

Comment 3 Fedora Update System 2026-11-09 01:50:49 UTC

FEDORA-2026-a83294f5ab (mingw-expat-2.9.0-1.fc43) has been pushed to the Fedora 43 stable repository.
If problem still persists, please make note of it in this bug report.