Home / mailings [USN-8705-2] OpenZFS vulnerability
Posted on 01 September 2026
Ubuntu Security==========================================================================Ubuntu Security Notice USN-8705-2
August 31, 2026
zfs-linux vulnerability
==========================================================================
A security issue affects these releases of Ubuntu and its derivatives:
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
Summary:
OpenZFS could be made to run programs as an administrator.
Software Description:
- zfs-linux: OpenZFS file system for Linux
Details:
USN-8705-1 fixed vulnerabilities in OpenZFS. This update provides the
corresponding fix for OpenZFS on Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.
Original advisory details:
It was discovered that OpenZFS incorrectly handled authorization checks for
certain ioctl operations on Linux. A local attacker could possibly use this
issue to perform pool-administrative operations or access privileged
information, resulting in an authorization bypass.
Update instructions:
The problem can be corrected by updating your system to the following
package versions:
Ubuntu 20.04 LTS
libuutil1linux 0.8.3-1ubuntu12.18+esm1
Available with Ubuntu Pro
libzfs2linux 0.8.3-1ubuntu12.18+esm1
Available with Ubuntu Pro
zfs-dkms 0.8.3-1ubuntu12.18+esm1
Available with Ubuntu Pro
zfsutils-linux 0.8.3-1ubuntu12.18+esm1
Available with Ubuntu Pro
Ubuntu 18.04 LTS
libuutil1linux 0.7.5-1ubuntu16.12+esm1
Available with Ubuntu Pro
libzfs2linux 0.7.5-1ubuntu16.12+esm1
Available with Ubuntu Pro
zfs-dkms 0.7.5-1ubuntu16.12+esm1
Available with Ubuntu Pro
zfsutils-linux 0.7.5-1ubuntu16.12+esm1
Available with Ubuntu Pro
After a standard system update you need to reboot your computer to make all the necessary changes.
References:
https://ubuntu.com/security/notices/USN-8705-2
https://ubuntu.com/security/notices/USN-8705-1
CVE-2026-79619
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