CVE-2026-79619 OpenZFS: user-namespace capability check allows unprivileged local authorization bypass
Unprivileged local users can bypass authorization checks in OpenZFS via user namespaces to perform administrative pool operations and fault injection.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-79619?
CVE-2026-79619 is a high-severity authentication bypass vulnerability in OpenZFS, published on 26 Aug 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
On Linux, several OpenZFS ioctl authorization checks accept a capability held only within a user-created, unprivileged namespace as equivalent to real host privilege, allowing an unprivileged local user to perform operations that should require root. Affected operations include pool-administrative operations (eg create, import, destroy), pool event log access (zpool events) and fault injection (zinject). Exploiting the problem requires only that the local user is permitted to open /dev/zfs (governed by local device permissions) and that the kernel permits unprivileged user namespace creation. No prior access to the target pool or its underlying devices is needed.
Weakness: CWE-863
Which versions are affected by CVE-2026-79619?
How do I fix CVE-2026-79619?
Apply the vendor's patch.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-79619 being exploited?
There is no known exploitation of CVE-2026-79619 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-79619, ECHO-a835-6f03-ef3a, GHSA-5v2p-vxxv-r62r, GHSA-mhf5-q8gw-qg9v, UBUNTU-CVE-2026-79619, USN-8705-1 and 1 more.