Skip to content
Fencer Vulns
high 7.3

CVE-2026-79619 json

OpenZFS: user-namespace capability check allows unprivileged local authorization bypass

published 2026-08-26 2 mo ago modified 2026-08-28 2 mo ago also EUVD-2026-66419

cvss
7.3
version 4.0, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 9%
public exploits
0
none known

Summary

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.

Patch / fix

  • OpenZFS OpenZFS 2.2.11, 2.3.9, 2.4.4
  • zfs-linux Debian 13 2.3.9-0+deb13u1
  • zfs-linux Debian 14 2.4.4-1

debian advisories DEBIAN-CVE-2026-79619

  • zfs-linux Ubuntu 22.04 LTS 2.1.5-1ubuntu6~22.04.7
  • zfs-linux Ubuntu 24.04 LTS 2.2.2-0ubuntu9.5
  • zfs-linux Ubuntu 26.04 LTS 2.4.1-1ubuntu5.1
  • zfs-linux Ubuntu Pro 18.04 LTS 0.7.5-1ubuntu16.12+esm1
  • zfs-linux Ubuntu Pro 20.04 LTS 0.8.3-1ubuntu12.18+esm1

ubuntu advisories UBUNTU-CVE-2026-79619

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
2 mo ago

Exploit prediction

0.20% chance of exploitation in the next 30 days, higher than 9% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
CNA 4.0 7.3 CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

Affected products

  • OpenZFS OpenZFS

Classification

Weakness

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.