CVE-2026-49425 Kernel stack disclosure in 32-bit compatibility support

Medium 5.5 Published 19 Aug 2026 Updated 26 Aug 2026

An unprivileged user can read uninitialized kernel stack data via the 32-bit compatibility kevent handler, potentially exposing sensitive information.

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-2026-49425?

CVE-2026-49425 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

The compat32 kevent() handler translates a 64-bit kevent struct into a stack- declared 32-bit struct. It did not first zero the stack struct.

An unprivileged user may observe a small amount of uninitialized kernel stack data, which may contain sensitive information.

Weakness: CWE-908

Which versions are affected by CVE-2026-49425?

It affects 1 product.

Products include Freebsd Freebsd.

How do I fix CVE-2026-49425?

No fix has been published for CVE-2026-49425 yet. Limit exposure of the affected software until one is available.

Is CVE-2026-49425 being exploited?

There is no known exploitation of CVE-2026-49425 in the wild and no public exploit code.

All Freebsd Freebsd vulnerabilities

Sources

Also known as GHSA-jjwm-g4j5-q96v.