What’s Vulnerable › Vulnerabilities
CVE-2026-49429: Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl
- Severity: high (CVSS 7.8 v3.1)
- Exploited in the wild: not listed in CISA KEV
- EPSS: 0.2% probability of exploitation in the next 30 days
- Public exploit or detection template: none known
- Published: 2026-08-19 · updated 2026-09-01
- Weakness: CWE-122
Description
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 products
- FreeBSD: 14.3, 14.3-p1, 14.3-p10, 14.3-p11, 14.3-p12, 14.3-p13 (+32)
References
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