Race condition in Linux kernel - CVE-2026-46295

Vulnerability identifier: #VU134234

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-46295

CWE-ID: CWE-362

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 a race condition in __kvm_apic_update_irr and KVM x86 LAPIC interrupt handling when synchronizing posted interrupts to the IRR in nested virtualization. A local user can trigger the race during nested VM interrupt delivery to cause a denial of service.

The issue causes a spurious kernel WARNING and a wasted L2 VM-Enter/VM-Exit cycle, while the pending interrupt is not lost.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-ibm (Ubuntu package)
linux-oem-7.0 (Ubuntu package)
linux-azure (Ubuntu package)
linux-aws (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - addressed in versions 7.0.0-28.28, 7.0.0-28.28.1, 7.0.0-1003.4, 7.0.0-1008.8
linux-ibm (Ubuntu package) - addressed in versions 7.0.0-1008.8, 7.0.0-1010.10
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1009.9
linux-azure (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1010.10
linux-aws (Ubuntu package) - addressed in versions 7.0.0-1009.9, 7.0.0-1015.15

• https://git.kernel.org/stable/c/33fd0ccd2590b470b65adcca288615ad3b5e3e06
• https://git.kernel.org/stable/c/4b6b06a8b12bfd95f9015074b1430c1480908073
• https://git.kernel.org/stable/c/bb1703949dcaa9a49c338dee075f659f4634214d

• Race condition in Linux kernel x86 kvm
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-ibm
• Ubuntu update for linux-azure
• Ubuntu update for linux-aws