CVE-2026-43364
kernel: ublk: fix NULL pointer dereference in ublk_ctrl_set_size()
Severity
ModerateRed Hat Product Security
CVSS 3.1
Review impact separately from score.
Published · May 8, 2026
Updated · June 28, 2026
Description
A flaw was found in the Linux kernel's ublk subsystem. A local user can trigger a NULL pointer dereference by sending an UPDATE_SIZE command to a ublk device that has been added but not yet started, or one that has been stopped. This occurs due to insufficient state validation before dereferencing ub->ub_disk. Successful exploitation of this vulnerability could lead to a system crash, resulting in a Denial of Service (DoS).
CVSS score applicability
The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.
Mitigation
No mitigation is specified in collected source.
CVSS / CWE
CVSS 3.1 · 5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CWE-476 · NULL Pointer Dereference