NULL pointer dereference in Linux kernel - CVE-2026-98593

Vulnerability identifier: #VU156896

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-2026-98593

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 through a potential kernel crash.

The vulnerability exists due to a NULL pointer dereference in the Linux kernel s390 debug_info_copy() function when copying a debug area after debug_register_static() fails and clears its pointers without resetting its bounds. A local user can trigger copying of the affected area by opening its view file or through debug_dump() to cause a denial of service.

Linux kernel
Ubuntu
linux-nvidia-tegra (Ubuntu package)
linux-nvidia-tegra-igx (Ubuntu package)
linux-nvidia-tegra-5.15 (Ubuntu package)
linux (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-aws (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-nvidia-tegra (Ubuntu package) - update to 5.15.0-1070.72
linux-nvidia-tegra-igx (Ubuntu package) - update to 5.15.0-1059.59
linux-nvidia-tegra-5.15 (Ubuntu package) - update to 5.15.0-1070.72~20.04.1
linux (Ubuntu package) - update to 7.0.0-42.42
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
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/012bfcd5a51082d5a65f096dfb9ca652b5267965
• https://git.kernel.org/stable/c/13decd3b3b3a4d8a2e603fb8c9ffde0c6be3c225
• https://git.kernel.org/stable/c/2de9c458cc49d8db6408a7c5fbf0c7c94fe4d52b
• https://git.kernel.org/stable/c/33f706884821da9cb55b650b7b1d4f2bdf800137
• https://git.kernel.org/stable/c/9c6af88fbefbe77608b77409df23a1617e28398c
• https://git.kernel.org/stable/c/a19bede30f0da5ae56782edac62b5998a7434cba
• https://git.kernel.org/stable/c/c593f38e1cdb92f87d01be4c4e5ac12417b1454b

• NULL pointer dereference in Linux kernel s390 kernel
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx
• Ubuntu update for linux, linux-aws, linux-aws-5.15 and more