CVE-2026-58087: The GETALL and SETALL commands in semctl(2) recorded the number of semaphores in the target set, dropped the lock…
CVE-2026-58087 · Severity: high · CVSS 7.8 · Published 2026-08-19
The GETALL and SETALL commands in semctl(2) 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 the sequence number wraps after 0x8000 create/destroy cycles. By rapidly destroying and recreating semaphore sets at the same index, another process can cause the sequence number to wrap, allowing a set with a different number of semaphores to pass validation. The subsequent copy then reads or writes past the end of the allocated buffer.
An unprivileged local user can trigger out-of-bounds reads and writes on kernel heap memory, potentially leading to privilege escalation.
No. Junglewise Threat Intelligence has no report of CVE-2026-58087 being exploited in the wild.
How severe is CVE-2026-58087?
High severity, with a CVSS score of 7.8, published 19 August 2026.
Which products and versions are affected?
Freebsd. The advisory does not name versions.
Is there a fix for CVE-2026-58087?
No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
Am I affected by CVE-2026-58087?
Check whether you run Freebsd. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.