CVE-2026-58089 hwpmc fails to detach PMCs during exec credential transitions

When a process calls execve2 to execute a setuid or setgid image, hwpmc4 is supposed to detach PMCs owned by unprivileged processes. An inverted check meant that this scenario was not handled properly. An unprivileged local user who has attached PMCs to a process can continue monitoring it after...

CVE-2026-58089

FreeBSD 's hwpmc(4) driver (hardware performance monitoring counters) contains a logic flaw in its handling of execve(2) credential transitions. An inverted check meant that PMCs owned by unprivileged processes were not detached when a target process executed a setuid or setgid binary, allowing a...