CVE-2026-11861 Red Hat CVE debrief

Who should care

System administrators and security teams responsible for FreeIPA and Active Directory configurations should assess exposure and prioritize remediation efforts. This includes reviewing and updating FreeIPA configurations, implementing additional authentication checks, and monitoring for suspicious activity related to TGS impersonation. Affected operator, platform, vulnerability-management, and security-team impact should be carefully evaluated to ensure a

Why it matters

This critical vulnerability allows Active Directory users to bypass authentication for FreeIPA services, potentially leading to privilege escalation and unauthorized access. System administrators and security teams should assess exposure and prioritize remediation efforts.

• Potential privilege escalation within the FreeIPA domain for authenticated Active Directory users
• Bypass of authentication mechanisms for FreeIPA services
• Possible unauthorized access to FreeIPA resources

Technical summary

The vulnerability occurs because FreeIPA services do not verify Privilege Attribute Certificate (PAC) certificates when a trust relationship is configured between FreeIPA and Active Directory. This allows Active Directory users to impersonate a client name in the Ticket Granting Service (TGS) and bypass authentication for FreeIPA services, including the portal, SMB server, and LDAP directory. Affected product deployments should assess their configurations and prioritize remediation efforts to prevent potential privilege escalation and unauthorized access.

Defensive priority

High priority for authentication and authorization checks

Recommended defensive actions

• Review and update FreeIPA configurations to enforce PAC certificate verification
• Implement additional authentication checks for Active Directory users
• Monitor for suspicious activity related to TGS impersonation
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The vulnerability was reported by Red Hat and is tracked as CVE-2026-11861. FreeIPA versions prior to 4.13.3 are affected, along with Red Hat Enterprise Linux 7, 8, 9, and 10. Affected deployments should verify their configurations and assess exposure. The vulnerability allows Active Directory users to impersonate a client name in the Ticket Granting Service (TGS) due to FreeIPA services not verifying Privilege Attribute Certificate (PAC) certificates.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.