CVE-2026-43364

MEDIUM EPSS 2.2%
Published May 8, 20261mo ago · Modified Jun 17, 20262w ago
5.5 CVSS 3.1
Medium
Find Similar
Published May 8, 2026 1mo ago
Last Modified Jun 17, 2026 2w ago

Description

In the Linux kernel, the following vulnerability has been resolved: ublk: fix NULL pointer dereference in ublk_ctrl_set_size() ublk_ctrl_set_size() unconditionally dereferences ub->ub_disk via set_capacity_and_notify() without checking if it is NULL. ub->ub_disk is NULL before UBLK_CMD_START_DEV completes (it is only assigned in ublk_ctrl_start_dev()) and after UBLK_CMD_STOP_DEV runs (ublk_detach_disk() sets it to NULL). Since the UBLK_CMD_UPDATE_SIZE handler performs no state validation, a user can trigger a NULL pointer dereference by sending UPDATE_SIZE to a device that has been added but not yet started, or one that has been stopped. Fix this by checking ub->ub_disk under ub->mutex before dereferencing it, and returning -ENODEV if the disk is not available.

CVSS Details

Base Score
5.5
Exploitability
1.8
Impact
3.6
Vector string
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack Vector Local
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High

Threat Intelligence

EPSS Exploit Probability
2.2% percentile
Exploit & Patch Status
No Known Exploit
Patch Available

Weaknesses 1

CWE-476 NULL Pointer Dereference Memory Safety

Affected Products 5

VendorProductVersionRange
linuxlinux_kernel*≥6.16  –  <6.18.20
linuxlinux_kernel*≥6.19  –  <6.19.9
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any
linuxlinux_kernel7.0any

References 3

  • git.kernel.org https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1
    Patch

Remediation

  • git.kernel.org https://git.kernel.org/stable/c/25966fc097691e5c925ad080f64a2f19c5fd940a
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/c28d945bfa92e15147e93b73f95345b9bec979b0
    Patch
  • git.kernel.org https://git.kernel.org/stable/c/f13fe6794726755a43090cb680c4c58cea6aa5f1
    Patch