CVE-2026-49429
Published:August 19, 2026
Updated:September 24, 2026
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 Packages
https://github.com/freebsd/freebsd-src.git (GITHUB):
Affected version(s) >=release/15.0.0 <release/15.0.0-p11Fix Suggestion:
Update to version release/15.0.0-p11https://github.com/freebsd/freebsd-src.git (GITHUB):
Affected version(s) >=release/14.4.0 <release/14.4.0-p7Fix Suggestion:
Update to version release/14.4.0-p7https://github.com/freebsd/freebsd-src.git (GITHUB):
Affected version(s) =release/15.1.0 <release/15.1.0-p1Fix Suggestion:
Update to version release/15.1.0-p1https://github.com/freebsd/freebsd-src.git (GITHUB):
Affected version(s) >=release/14.3.0 <release/14.3.0-p16Fix Suggestion:
Update to version release/14.3.0-p16Related Resources (1)
Do you need more information?
Contact UsCVSS v4
Base Score:
8.5
Attack Vector
LOCAL
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
LOW
User Interaction
NONE
Vulnerable System Confidentiality
HIGH
Vulnerable System Integrity
HIGH
Vulnerable System Availability
HIGH
Subsequent System Confidentiality
NONE
Subsequent System Integrity
NONE
Subsequent System Availability
NONE
CVSS v3
Base Score:
7.8
Attack Vector
LOCAL
Attack Complexity
LOW
Privileges Required
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
HIGH
Weakness Type (CWE)
Heap-based Buffer Overflow
EPSS
Base Score:
0.17