{"id":"CVE-2026-49429","aliases":["EUVD-2026-62239"],"status":"published","title":"Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl","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.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","severity":{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"adp","from":"cve"},"epss":{"day":"2026-11-09","score":0.00153,"percentile":0.04443,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-122"],"published":"2026-08-19T05:15:21Z","modified":"2026-11-09T20:10:00Z","products":[{"vendor":"freebsd","product":"freebsd"}],"references":[{"url":"https://security.freebsd.org/advisories/FreeBSD-SA-26:40.zfs.asc","tags":["vendor-advisory","Vendor Advisory"]}],"sources":{"cve":[{"id":"CVE-2026-49429","title":"Kernel heap overflow in ZFS_IOC_USERSPACE_MANY ioctl","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.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","status":"published","published":"2026-08-19T05:15:21.198Z","modified":"2026-08-20T03:55:49.215Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"adp"}],"cwes":["CWE-122"],"updated_at":"2026-11-02T13:35:10.963527Z"}],"euvd":[{"id":"EUVD-2026-62239","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.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","status":"published","published":"2026-08-19T05:15:21Z","modified":"2026-08-20T03:55:49Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"updated_at":"2026-11-02T18:01:40.451894Z"}],"nvd":[{"id":"CVE-2026-49429","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.\n\nA local user with the \"userused\" delegated ZFS permission can trigger a kernel heap overflow via the ZFS_IOC_USERSPACE_MANY ioctl, potentially escalating privileges.","status":"published","published":"2026-08-19T06:17:42.513Z","modified":"2026-11-09T20:10:00.2Z","cvss":[{"version":"3.1","score":7.8,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-122"],"updated_at":"2026-11-09T22:15:51.558963Z"}]}}