CVE-2026-49429
Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl
CVSS Score
0.0
EPSS Score
0.0%
EPSS Percentile
0th
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.
| CWE | CWE-122 |
| Vendor | freebsd |
| Product | freebsd |
| Published | Aug 19, 2026 |
Stay Ahead of the Next One
Get instant alerts for freebsd freebsd
Be the first to know when new unknown vulnerabilities affecting freebsd freebsd are published — delivered to Slack, Telegram or Discord.
Get Free Alerts →
Free · No credit card · 60 sec setup
Affected Versions
FreeBSD / FreeBSD
15.1-RELEASE < p1 15.0-RELEASE < p11 14.4-RELEASE < p7 14.3-RELEASE < p16
References
Credits
Yuxiang Yang, Yizhou Zhao, Ao Wang, Xuewei Feng, Qi Li, and Ke Xu from Tsinghua University using GLM-5.1 from Z.ai Emmanuel Genier at Quarkslab