Bug 2531348 (CVE-2026-88834)

Summary: CVE-2026-88834 busybox: busybox: httpd user existence oracle in non-default shadow-disabled builds
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security <prodsec-ir-bot>
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Priority: low    
Version: unspecifiedCC: security-response-team
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in BusyBox's httpd web server. When configured with system password authentication, a user existence oracle may exist in certain build configurations. An attacker could distinguish existing from non-existing usernames by observing authentication failure behavior. Impact is limited to username enumeration and requires non-default compile options or uncommon password file states; default BusyBox builds with shadow password support are not affected.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2026-09-10 09:47:10 UTC
A vulnerability was found in the BusyBox httpd Basic Authentication handler (networking/httpd.c) when configured to authenticate against system passwords. A missing else clause after a failed getspnam_r() call creates an observable behavioral difference between authentication failures for existing and non-existing system users. Existing user with wrong password: connection reset. Non-existing user: clean HTTP 401.