CVE-2026-58087

A heap out-of-bounds access vulnerability exists in the semctl(2) system call on FreeBSD . The GETALL and SETALL commands suffer from a flaw where they allocate a buffer based on a semaphore count, drop a lock, and then reacquire it. While a sequence-number check is intended to prevent use of a r...

CVE-2026-58087: Integer Underflow (Wrap or Wraparound)

The GETALL and SETALL commands in semctl2 recorded the number of semaphores in the target set, dropped the lock protecting the set, allocated a buffer sized for that count, and reacquired the lock. A sequence-number check was used to verify that the set had not been replaced in the interim, but t...