CVE-2026-104048: Sssd: sssd: authorization bypass via cross-domain username collision in hbac evaluation

Severity: high (CVSS 8.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: yes
Published: 2026-10-06 · updated 2026-10-09
Weakness: CWE-1025

Description

A flaw was found in SSSD. In trust-enabled identity management environments, SSSD evaluates Host-Based Access Control (HBAC) rules by stripping domain qualifiers and comparing only short usernames. An authenticated user in a trusted domain who shares the same username as an authorized local account can bypass access policies and gain unauthorized access to protected services or hosts.

Affected products

[UNKNOWN] sssd: 2.12.0
Red Hat Enterprise Linux: 7.0, 8.0, 9.0, 10.0
Red Hat OpenShift Container Platform 4.18: 4.0

References

https://access.redhat.com/security/cve/CVE-2026-104048
https://bugzilla.redhat.com/show_bug.cgi?id=2478613
https://bugzilla.redhat.com/show_bug.cgi?id=2478613

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