CVE-2026-58094 TOCTOU race in POSIX shared memory large page configuration
A race condition in FreeBSD's POSIX shared memory configuration allows local attackers to escalate privileges by exploiting a TOCTOU flaw.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-58094?
CVE-2026-58094 is a high-severity vulnerability in Freebsd Freebsd, published on 26 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
The FIOSSHMLPGCNF ioctl(2) operation configures the page size for a largepage shared memory object. This is intended to be used immediately after creating the object, before any memory is allocated for the object. The handler checked whether a page size had already been configured without holding the rangelock. Two concurrent callers could both observe an unconfigured object and set conflicting page sizes, leaving the object in an inconsistent state.
An unprivileged local user can exploit this race to escalate privileges.
Weakness: CWE-367
Which versions are affected by CVE-2026-58094?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-58094?
No fix has been published for CVE-2026-58094 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-58094 being exploited?
There is no known exploitation of CVE-2026-58094 in the wild and no public exploit code.