NULL pointer dereference in Linux kernel - CVE-2026-98637

Vulnerability identifier: #VU156949

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-2026-98637

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 inconsistent VM-wide SVE feature state leading to a NULL pointer dereference in the Linux kernel's arm64 protected KVM implementation when handling an SVE initialization failure. A local user can trigger floating-point access in a guest on a subsequently registered vCPU to cause a denial of service, as SVE setup is skipped and sve_load_state() receives a NULL sve_state pointer.

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/a1b3c788ad31837e348075e93dbba3f447492776
• https://git.kernel.org/stable/c/bd46b41f412fb81c50bac1a0929ec31320f3a807
• https://git.kernel.org/stable/c/f0cd8ffae092cc1b9d7cfa9188ed5a88a374adcb

• NULL pointer dereference in Linux kernel hyp nvhe
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more