CVE-2026-49430
HighCVSS 7.8Exploitation Probability (EPSS)
Low risk6th percentile - higher than 6% of all known CVEs
Summary
The ZFS_IOC_RECV_NEW ioctl, in the heal receive path, similarly truncated a 64-bit payload size to a 32-bit integer for allocation, then used the original 64-bit size as the length for a byteswap operation. A local user with the "receive" delegated ZFS permission can trigger kernel memory corruption via ZFS_IOC_RECV_NEW by sending a crafted receive stream in heal mode.
Risk Assessment
A local user with appropriate permissions can cause kernel memory corruption, potentially leading to system crash or privilege escalation.
Recommendation
Apply the vendor patch that fixes the size truncation in the ZFS_IOC_RECV_NEW ioctl. Update the system to a patched version.
Other vulnerabilities in FreeBSD ZFS
See all- CVE-2026-49431Low
The ZFS_IOC_SET_PROP ioctl, used by zfs-set(8), incorrectly validated the calling user such that an unprivileged user is able to set metadata on a dataset indicating that the dataset has received properties from a zfs-recv(8) stream. Any local user can set the internal ZFS metadata flag "$hasrecvd" on datasets via ZFS_IOC_SET_PROP.
- CVE-2026-49429High
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.
Original NVD description (English source)
The ZFS_IOC_RECV_NEW ioctl, in the heal receive path, similarly truncated a 64-bit payload size to a 32-bit integer for allocation, then used the original 64-bit size as the length for a byteswap operation. A local user with the "receive" delegated ZFS permission can trigger kernel memory corruption via ZFS_IOC_RECV_NEW by sending a crafted receive stream in heal mode.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS