Incomplete cleanup in Linux kernel - CVE-2026-98471

Vulnerability identifier: #VU156769

CSH Severity: Low

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

CVE-ID: CVE-2026-98471

CWE-ID: CWE-459

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to potentially disclose sensitive guest data left in CPU caches.

The vulnerability exists due to incomplete cache cleanup in the Linux kernel KVM SEV subsystem when performing intra-host VM migration and subsequently destroying the source VM. A local user can potentially exploit residual cached data to disclose sensitive guest information because converting the source VM to a non-SEV VM prevents its memory reclamation flows from triggering cache maintenance.

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/37dfb676fafd1eef36fe0bb649607afbb0d5521b
• https://git.kernel.org/stable/c/93de2a6a4b91b72607136dd656edf03fb399d27f
• https://git.kernel.org/stable/c/d4cc2dff12116a700add601c0262132cc26e1b2c

• Incomplete cleanup in Linux kernel kvm svm
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more