NULL pointer dereference in Linux kernel - CVE-2026-98564

Vulnerability identifier: #VU156868

CSH Severity: Low

CVSS v4: 5.6 [CVSS:4.0/AV:L/AC:L/AT:P/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98564

CWE-ID: CWE-476

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local privileged user to cause a denial of service by triggering a kernel crash.

The vulnerability exists due to a null pointer dereference in the Linux kernel MT7530 switch driver's interrupt teardown path when handling a late PHY interrupt during switch removal. A local privileged user can exploit interrupt dispatch after the corresponding interrupt mapping has been disposed of to cause handle_nested_irq() to dereference a null interrupt descriptor and crash the kernel.

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/0d80ba0a204c6a16bd7778b50de578dff107c0fe
• https://git.kernel.org/stable/c/2357c682f6eaf639dec88c68b3c0c93a3b802635
• https://git.kernel.org/stable/c/f306e465b5a2091cd3fe3dd0feb10cfc94cfb2f8

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