Privilege Escalation Vulnerability in FreeBSD 15.0 Kernel Structure

CVE-2026-58092

What is CVE-2026-58092?

In FreeBSD 15.0, a flaw in the kernel's handling of user credentials allows certain mac_do rules to incorrectly assign the primary group ID, potentially facilitating unauthorized privilege escalation. Specifically, the transition from the previous credential system to a dedicated primary group ID field was insufficiently addressed in the group_is_primary() function. By exploiting meticulously crafted mac_do rules, an attacker can jeopardize the integrity of user credentials, enabling a process to assume the identity associated with the 'wheel' group (ID 0). This scenario can be triggered under specific conditions, requiring the attacker to leverage user ID relationships defined in the system. Proper understanding of group ID management, coupled with effective system configuration, is crucial to mitigate the risk presented by this vulnerability.

References