CVE-2026-11861Authentication bypass in FreeIPA via Active Directory
A flaw was found in FreeIPA. When a trust relationship is configured between FreeIPA and Active Directory, Active Directory users can bypass authentication for FreeIPA services, including the portal, SMB server, and LDAP directory. This is possible by impersonating a client name in the Ticket Granting Service (TGS) due to FreeIPA services not verifying Privilege Attribute Certificate (PAC) certificates. This vulnerability could allow an authenticated Active Directory user to escalate their privileges within the FreeIPA domain.
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FreeIPA has a critical vulnerability allowing Active Directory users to bypass authentication and impersonate other clients. This affects core services like LDAP and SMB when a trust relationship is active, due to a failure in verifying Kerberos PAC certificates.
Severity
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:NCWE-266EPSS
No EPSS score yet (CVE may be too fresh).
Technical description
A flaw was found in FreeIPA. When a trust relationship is configured between FreeIPA and Active Directory, Active Directory users can bypass authentication for FreeIPA services, including the portal, SMB server, and LDAP directory. This is possible by impersonating a client name in the Ticket Granting Service (TGS) due to FreeIPA services not verifying Privilege Attribute Certificate (PAC) certificates. This vulnerability could allow an authenticated Active Directory user to escalate their privileges within the FreeIPA domain.