CVE-2026-102631
Description
A flaw was found in authd. When an external Identity Provider (IdP) reassigns a username or email address previously associated with a deleted account, authd incorrectly falls back to matching only the username during authentication without verifying the unique provider identifier. A user logging in with the reassigned identity inherits the previous user's local account and home directory, resulting in unauthorized access to sensitive data and credentials such as SSH keys and cloud API tokens.
Statement
This vulnerability is rated as Moderate impact because exploitation depends on external identity provider account reassignments rather than direct unauthorized remote access, constraining the attack surface to specific account lifecycle events. Although local credential compromise can occur upon identity reuse, authd is not included or supported in Red Hat Enterprise Linux or other Red Hat products, which instead rely on native identity solutions such as SSSD.
Understanding the Weakness (CWE)
Access Control
Technical Impact: Gain Privileges or Assume Identity
The attacker can gain access to otherwise unauthorized resources.
Integrity,Confidentiality,Other
Technical Impact: Modify Application Data; Modify Files or Directories; Read Application Data; Read Files or Directories; Other
Race conditions such as this kind may be employed to gain read or write access to resources not normally readable or writable by the user in question.
Integrity,Other
Technical Impact: Modify Application Data; Other
The resource in question, or other resources (through the corrupted one) may be changed in undesirable ways by a malicious user.
Non-Repudiation
Technical Impact: Hide Activities
If a file or other resource is written in this method, as opposed to a valid way, logging of the activity may not occur.
Non-Repudiation,Integrity
Technical Impact: Modify Files or Directories
In some cases it may be possible to delete files that a malicious user might not otherwise have access to -- such as log files.
Frequently Asked Questions
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