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VULNERABILITIES

CVE-2026-49429 Details

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.

Metrics

CVSS 3.x Severity and Vector Strings:

CNA: CISA-ADPCVSS-B:7.8 HIGHVector:CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://security.freebsd.org/advisories/FreeBSD-SA-26:40.zfs.asc [email protected]Vendor Advisory

Weakness Enumeration

CWE-IDCWE NameSource
CWE-122Heap-based Buffer Overflow[email protected]

Affected Products

ProductVersions
freebsd freebsd
14.3 -
14.3 p1
14.3 p10
14.3 p11
14.3 p12

CPE

  • cpe:2.3:o:freebsd:freebsd:14.3:-:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p1:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p10:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p11:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p12:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p13:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p14:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p15:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p2:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p3:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p4:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p5:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p6:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p7:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p8:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.3:p9:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:-:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p1:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p2:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p3:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p4:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p5:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:p6:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:14.4:rc1:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:-:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p1:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p10:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p2:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p3:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p4:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p5:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p6:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p7:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p8:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.0:p9:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.1:-:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.1:rc2:*:*:*:*:*:*
  • cpe:2.3:o:freebsd:freebsd:15.1:rc3-p1:*:*:*:*:*:*

Remediation

  • No remediation found in references.

Change History

4 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-49429
NVD Published Date:
Aug 19, 2026
NVD Last Modified:
Sep 1, 2026
Source:
[email protected]