CVE-2026-49431 Incorrect user validation in ZFS_IOC_SET_PROP ioctl

Low 3.3 Published 19 Aug 2026 Updated 26 Aug 2026

An unprivileged local user can incorrectly set internal ZFS metadata flags on datasets, bypassing intended authorization checks.

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-2026-49431?

CVE-2026-49431 is a low-severity missing authorization 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 ZFS_IOC_SET_PROP ioctl, used by zfs-set(8), incorrectly validated the calling user such that an unprivileged user is able to set metadata on a dataset indicating that the dataset has received properties from a zfs-recv(8) stream.

Any local user can set the internal ZFS metadata flag "$hasrecvd" on datasets via ZFS_IOC_SET_PROP.

Weakness: CWE-863

Which versions are affected by CVE-2026-49431?

It affects 1 product.

Products include Freebsd Freebsd.

How do I fix CVE-2026-49431?

No fix has been published for CVE-2026-49431 yet. Limit exposure of the affected software until one is available.

Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.

Is CVE-2026-49431 being exploited?

There is no known exploitation of CVE-2026-49431 in the wild and no public exploit code.

All Freebsd Freebsd vulnerabilities

Sources

Also known as GHSA-hrxx-hfqm-f933.