Improper locking in Linux kernel - CVE-2026-90043

Vulnerability identifier: #VU150245

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-90043

CWE-ID: CWE-667

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to compromise confidentiality, integrity, and availability.

The vulnerability exists due to improper locking in the zram slot-locking mechanism when access-time values are stored for zram slots. A local user can trigger concurrent access to the same zram slot to compromise confidentiality, integrity, and availability.

The issue affects 64-bit big-endian systems when zram access-time tracking is enabled.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

• https://git.kernel.org/stable/c/052b6b2d5fe97547bd2cdb73fa894f6cfea68b11
• https://git.kernel.org/stable/c/a8b5875741d416703e19ad8eeac6fce8a12bd6e4

• Improper locking in Linux kernel block zram driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more