Bug 2567690 (CVE-2026-123158)

Summary: CVE-2026-123158 openssh: OpenSSH: Password authentication bypass via password hash misinterpretation
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedCC: akhatavk, aos-team-art-private, asdas, cchiang, dpaolell, jdelft, jupierce, lgarciaa, mbiarnes, ppalepu, ppostler, prdhamdh, rhel-process-autobot, sghai, sidsharm, suppawar, vlaad, watson-tool-maintainers, yguenane
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in OpenSSH. When running on Linux systems utilizing the musl standard C library without Pluggable Authentication Modules (PAM), the SSH server can misinterpret input strings as password hashes. A remote, unauthenticated attacker can exploit this flaw by submitting a specially sized password, bypassing password authentication and gaining unauthorized access to affected accounts.
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Description OSIDB Bzimport 2026-11-05 22:18:16 UTC
sshd in OpenSSH before 10.6p2 on Linux, when musl libc is used without PAM, lacks a workaround for a password authentication bypass (related to misinterpretation of whether a string is intended to be a password hash). For some configurations of accounts, any password between 256 and 1024 characters succeeds. An example of a platform using musl libc without PAM is Alpine Linux.