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

The hwpmc(4) driver in FreeBSD contains a vulnerability where it fails to detach Performance Monitoring Counters (PMCs) owned by unprivileged processes during an execve(2) call to a setuid or setgid image. This is caused by an inverted check in the kernel, allowing a local unprivileged user to co...