NULL pointer dereference in Linux kernel - CVE-2026-98523

Vulnerability identifier: #VU156825

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98523

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service by triggering a kernel NULL pointer dereference.

The vulnerability exists due to a null pointer dereference in drm_fbdev_client_restore() when restoring a partially initialized fbdev client after its initial configuration fails. A local user can close a DRM file descriptor to trigger restoration of uninitialized framebuffer state and cause a denial of service.

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/11edd5b6735d2e1069ddce672b1836713647f7fb
• https://git.kernel.org/stable/c/1fca688e9443003e33cf30453e7a7560367656c9
• https://git.kernel.org/stable/c/a69c4b678db808c0d89abb8cedeaaac38d1ef182
• https://git.kernel.org/stable/c/fcbedba553a9c430079ee225df2dc7ab556a2f83

• NULL pointer dereference in Linux kernel drm clients driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more