CVE-2026-49429Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl
Updated under an hour ago ()
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No exploitation reported and no EPSS estimate yet.
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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
- 7.8 HIGH (v3.1, CISA ADP)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- CWE-122
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- freebsd
- NVD analysis
- Analyzed
- Record last updated
- Aug 20, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
FreeBSD FreeBSD freebsd:freebsd (from the name) | from 15.1-RELEASE before p1; from 15.0-RELEASE before p11; from 14.4-RELEASE before p7; from 14.3-RELEASE before p16 | CNA record |
freebsd freebsd freebsd:freebsd | 14.3; 14.3; 14.3; 14.3; 14.3; 14.3; 14.3; 14.3; and 30 more ranges | NVD |
References
- https://security.freebsd.org/advisories/FreeBSD-SA-26:40.zfs.ascvendor-advisory
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.