CVE-2026-43364

Year

2026

Published

May 8, 2026

Known Affected Devices

CVSS Score

N/A

What is CVE-2026-43364?

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.

FAQ

How severe is CVE-2026-43364?

CVE-2026-43364 has a CVSS score of N/A/10, rated as Unknown. Review the affected products list and apply vendor patches.

What does the CVSS score mean for CVE-2026-43364?

CVSS (Common Vulnerability Scoring System) rates vulnerability severity from 0.0 to 10.0. CVE-2026-43364 scores N/A/10 (Unknown). Scores 9.0–10.0 are Critical, 7.0–8.9 are High, 4.0–6.9 are Medium, and below 4.0 are Low.

Which devices are affected by CVE-2026-43364?

The list of devices confirmed to be affected by CVE-2026-43364 is shown in the "Affected Devices" section above. Check your firmware version against the vendor security advisory and apply the latest patch.

How do I fix or mitigate CVE-2026-43364?

Apply the latest firmware or software update from the vendor. Check the References section above for official advisories and patch notes. If no patch is available, consider disabling the affected feature or isolating the device from untrusted networks.