Bug 2524647

Summary: CVE-2026-76956 mingw-expat: libexpat: Denial of Service via hash flooding attack with crafted XML [fedora-all]
Product: [Fedora] Fedora Reporter: Laura Pardo <lpardo>
Component: mingw-expatAssignee: Richard W.M. Jones <rjones>
Status: ON_QA --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: rawhideCC: manisandro, rjones
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["64f3276e-f2a2-4cb7-baeb-ee466cb004d0"]}
Fixed In Version: Doc Type: ---
Doc Text:
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Clone Of: Environment:
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Regression: --- Mount Type: ---
Documentation: --- CRM:
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On:    
Bug Blocks: 2520124    

Description Laura Pardo 2026-08-26 19:35:18 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.

In libexpat 2.8.2 and 2.8.3 before 2.8.4, misinterpretation of getentropy's return code leads to insufficient entropy, which results in being vulnerable to hash flooding attacks, causing a denial of service via crafted XML content.

Comment 1 Fedora Update System 2026-09-03 13:53:52 UTC
FEDORA-2026-4a2ee61320 (mingw-expat-2.8.4-1.fc43) has been submitted as an update to Fedora 43.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-4a2ee61320

Comment 2 Fedora Update System 2026-09-03 13:53:53 UTC
FEDORA-2026-5660612c34 (mingw-expat-2.8.4-1.fc44) has been submitted as an update to Fedora 44.
https://bodhi.fedoraproject.org/updates/FEDORA-2026-5660612c34

Comment 3 Fedora Update System 2026-09-04 00:52:18 UTC
FEDORA-2026-9e9244744d has been pushed to the Fedora 45 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-9e9244744d`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-9e9244744d

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

Comment 4 Fedora Update System 2026-09-04 01:50:47 UTC
FEDORA-2026-5660612c34 has been pushed to the Fedora 44 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --refresh --advisory=FEDORA-2026-5660612c34`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-5660612c34

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

Comment 5 Fedora Update System 2026-09-04 16:25:00 UTC
FEDORA-2026-4a2ee61320 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-2026-4a2ee61320`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2026-4a2ee61320

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