Bug 2484620 (CVE-2026-50219)

Summary: CVE-2026-50219 expat: libexpat: Use-after-free vulnerability due to improper handler call depth tracking
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in libexpat. This vulnerability occurs because the library, in versions before 2.8.2, does not properly track handler call depth when certain XML parsing functions are invoked from within handlers during a policy violation. This oversight can lead to a use-after-free condition, which may result in information disclosure, integrity loss, or denial of service.
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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: 2486181, 2486180    
Bug Blocks:    

Description OSIDB Bzimport 2026-06-04 06:01:30 UTC
libexpat before 2.8.2 lacks handler call depth tracking for calls to XML_GetBuffer, XML_Parse, XML_ParseBuffer, XML_ParserFree, or XML_ParserReset from within handlers in cases of a policy violation. Thus, a use-after-free can occur,