VULNERABILITY INTELLIGENCE

CVE-2026-49429

CVSS score7.8 HIGH
EPSS probability0.15%
CISA KEVNot currently listed
Published2026-08-19
Last modified2026-09-01
CVSS vectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Description

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.

Weakness classification

  • secteam@freebsd.org: CWE-122

Primary references