CVE-2026-58100 Memory safety bugs in kqueue copy-on-fork implementation
A race condition in FreeBSD's kqueue implementation allows local attackers to trigger an out-of-bounds read and escalate privileges.
- 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-2026-58100?
CVE-2026-58100 is a high-severity vulnerability in Freebsd Freebsd, published on 15 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
kqueue_fork_copy_knote() indexed into the child's file descriptor table using a knote's file descriptor number without a bounds check. Because the child's table is copied before knotes are transferred, a concurrent thread in the parent could grow the parent's table and register knotes with file descriptor numbers beyond the end of the child's table, causing an out-of-bounds read.
An unprivileged local user may be able to exploit these races to escalate privileges.
Which versions are affected by CVE-2026-58100?
It affects 1 product.
Products include Freebsd Freebsd.
How do I fix CVE-2026-58100?
No fix has been published for CVE-2026-58100 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-58100 being exploited?
There is no known exploitation of CVE-2026-58100 in the wild and no public exploit code.
Other vulnerabilities in Freebsd Freebsd
Sources
Also known as GHSA-cvhg-28x6-2vj7.