Bug 2519777

Summary: CVE-2026-76781 qt5-qtwebengine: libxml2: NULL pointer dereference parsing nextCatalog without catalog attribute [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Ganesh <gnaik>
Component: qt5-qtwebengineAssignee: Jan Grulich <jgrulich>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: medium Docs Contact:
Priority: medium    
Version: epel10CC: jgrulich, kde-sig, kevin
Target Milestone: ---Keywords: Security, SecurityTracking
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Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["92b34854-680a-43a6-b19d-83bae9c17936"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2519776    

Description Ganesh 2026-08-19 17:30:02 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.

A NULL pointer dereference flaw was found in libxml2 XML catalog parsing. When a catalog contains a nextCatalog element without the mandatory catalog attribute, xmlParseXMLCatalogOneNode() returns NULL, but the nextCatalog deduplication loop dereferences the entry before the existing NULL check, crashing the application.