NULL pointer dereference in Linux kernel - CVE-2026-53328

Vulnerability identifier: #VU136724

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-53328

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.

The vulnerability exists due to improper handling of a NULL pointer state in scx_cgroup_move_task() when processing cgroup migration events under a sched_ext scheduler. A local user can trigger cgroup subtree_control changes to cause a kernel warning and destabilize the system.

The issue occurs when migration is driven by css identity rather than cgroup identity, allowing a legitimate css-only migration to reach the function with cgrp_moving_from unset.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-azure (Ubuntu package)
linux-oracle-7.0 (Ubuntu package)
linux-gcp-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-ibm (Ubuntu package)
linux-azure-7.0 (Ubuntu package)
linux-nvidia (Ubuntu package)
linux-nvidia-7.0 (Ubuntu package)
linux-raspi (Ubuntu package)
linux-nvidia-bos (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1011.11, 7.0.0-1014.14
linux-oracle-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13
linux-ibm (Ubuntu package) - update to 7.0.0-1013.13
linux-azure-7.0 (Ubuntu package) - update to 7.0.0-1014.14~24.04.1
linux-nvidia (Ubuntu package) - update to 7.0.0-1018.18
linux-nvidia-7.0 (Ubuntu package) - update to 7.0.0-1018.18~24.04.1
linux-raspi (Ubuntu package) - update to 7.0.0-1019.19
linux-nvidia-bos (Ubuntu package) - update to 7.0.0-2018.18

• https://git.kernel.org/stable/c/02e545c4297a26dbbc41df81b831e7f605bcd306
• https://git.kernel.org/stable/c/0ffcad63b19a1cadb475c9f405a93607fdcd0d7c
• https://git.kernel.org/stable/c/bc75f5951fac4e49d175c4433fc08fb1ec01172f
• https://git.kernel.org/stable/c/cdff2eb97be147d2ce52ac1327841068781f25dc

• NULL pointer dereference in Linux kernel sched
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0
• Ubuntu update for linux-oracle-7.0
• Ubuntu update for linux-azure
• Ubuntu update for linux-azure-7.0
• Ubuntu update for linux-nvidia
• Ubuntu update for linux-nvidia-bos
• Ubuntu update for linux-ibm
• Ubuntu update for linux-raspi
• Ubuntu update for linux-nvidia-7.0