Use-after-free in Linux kernel - CVE-2026-98286

Vulnerability identifier: #VU153740

CSH Severity: Low

CVSS v4: 5.7 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98286

CWE-ID: CWE-416

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 use-after-free in the Linux kernel drop_monitor component when per-CPU timers are rearmed by concurrently running alert work during teardown. A local user can trigger this teardown race to cause a denial of service.

Exploitation requires a memory allocation failure under memory pressure in an alert worker's reset function and subsequent unloading of the drop-monitor module. The remaining active timer then invokes a callback in freed module memory, triggering a kernel panic.

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/9616b0c67fbd8cc0b49de7b26cdf2ab33747c80e
• https://git.kernel.org/stable/c/bda4d9525fb91a2388ee09669421b8d505290864
• https://git.kernel.org/stable/c/c391a40f71886b28c082b47270f0e856fa3e1150

• Use-after-free in Linux kernel core
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more