Bug 2449783 (CVE-2026-4438)

Summary: CVE-2026-4438 glibc: glibc: Invalid DNS hostname returned via gethostbyaddr functions
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
Status: NEW --- QA Contact:
Severity: low Docs Contact:
Priority: low    
Version: unspecifiedCC: ashankar, codonell, dj, fweimer, pfrankli
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in the GNU C library (glibc). When applications use the `gethostbyaddr` or `gethostbyaddr_r` functions with a `nsswitch.conf` configuration that specifies glibc's DNS backend, the library may return an invalid DNS hostname. This violates the DNS specification and could lead to applications receiving incorrect hostname information, potentially impacting network operations or security decisions.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2450229, 2450233, 2450226, 2450227, 2450231, 2450235    
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Description OSIDB Bzimport 2026-03-20 21:02:39 UTC
Calling gethostbyaddr or gethostbyaddr_r with a configured nsswitch.conf that specifies the library's DNS backend in the GNU C library version 2.34 to version 2.43 could result in an invalid DNS hostname being returned to the caller in violation of the DNS specification.