Kernel memory corruption via ZFS_IOC_RECV_NEW ioctl in FreeBSD ZFS
CVE-2026-49430 Published on August 19, 2026
Kernel heap overflow in ZFS_IOC_RECV_NEW ioctl
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.
Weakness Type
Heap-based Buffer Overflow
A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc().
Products Associated with CVE-2026-49430
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Affected Versions
FreeBSD:- Version 15.1-RELEASE and below p1 is affected.
- Version 15.0-RELEASE and below p11 is affected.
- Version 14.4-RELEASE and below p7 is affected.
- Version 14.3-RELEASE and below p16 is affected.