Reachable assertion in Linux kernel - CVE-2026-98470

Vulnerability identifier: #VU156768

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-2026-98470

CWE-ID: CWE-617

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause a denial of service on a protected KVM host when panic_on_warn is enabled.

The vulnerability exists due to a reachable warning assertion in kvm_pkvm_ioctl_allowed() when handling an unknown VM ioctl in protected mode. A local user can issue ioctl(vm_fd, 0xdeadbeef) using a VM file descriptor to trigger a kernel warning that taints the host and causes a kernel panic when panic_on_warn is enabled.

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/49d9d295d69d07e850cae35933ba8519e2915f26
• https://git.kernel.org/stable/c/cc53eb5c6515e3221314624a22c9da9c80a67f63

• Reachable assertion in Linux kernel include asm
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more