CVE-2026-58084 Kernel stack disclosure via timer_settime(2)
An unprivileged local user can read uninitialized kernel stack memory via timer_settime(2) on FreeBSD, potentially exposing sensitive data.
- 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-2026-58084?
CVE-2026-58084 is a medium-severity vulnerability in Freebsd Freebsd, published on 19 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
To retrieve the previous timer value, the kernel calls realtimer_gettime(), which obtains the current time for the timer's clock. For a timer using CLOCK_TAI this can fail when no TAI offset has been configured, but the error return was not checked, so the uninitialized output buffer was copied to userspace.
An unprivileged local user can obtain uninitialized kernel stack memory by creating a POSIX timer with CLOCK_TAI and calling timer_settime(2), potentially disclosing sensitive kernel data.
Weakness: CWE-908
Which versions are affected by CVE-2026-58084?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-58084?
No fix has been published for CVE-2026-58084 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-58084 being exploited?
There is no known exploitation of CVE-2026-58084 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-p4v3-cw55-5mrc.