CVE-2026-49429

Summary

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.

Affected Software

VendorProductVersion RangeStatus
FreeBSDFreeBSD15.1-RELEASE < p1affected
FreeBSDFreeBSD15.0-RELEASE < p11affected
FreeBSDFreeBSD14.4-RELEASE < p7affected
FreeBSDFreeBSD14.3-RELEASE < p16affected

Weaknesses

  • CWE-122: CWE-122: Heap-based Buffer Overflow

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References