Vulnerability intelligence

CVE-2026-49429

The ZFS_IOC_USERSPACE_MANY ioctl, used by zfs-userspace(8), truncated a 64-bit output buffer size to a 32-bit integer for the kernel allocation, but used the original 64-bit size as the buffer limit when writing records. A local user with the "userused" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.

CVSS Score

7.8

High

EPSS — Exploit Probability

0.2%

Riskier than 4% of all CVEs · checked 2026-09-30

Exploitation

Not in CISA KEV

KEV does not include every exploited vulnerability

Remediation

unknown

Check vendor advisories