CVE-2026-49429highCWE-122

CVE-2026-49429: high-severity vulnerability in FreeBSD

Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl

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21Vexday Risk Score

No sign of exploitation. No public exploitation artifact known so far.

ssvc Trackcvss 7.8epss 0.2%
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:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Affected products
FreeBSD · FreeBSD
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