Use-after-free in Linux kernel - CVE-2026-64286

Vulnerability identifier: #VU139698

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-2026-64286

CWE-ID: CWE-416

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 improper handling of a stale pointer in flush_hyp_vcpu() when copying the host vCPU context into the hyp private vCPU. A local user can provide a crafted __hyp_running_vcpu value to cause a denial of service.

The issue occurs on arm64 KVM with pKVM at EL2 during vCPU context handling.

Linux kernel
Debian Linux
Ubuntu
linux (Debian package)
linux (Ubuntu package)
linux-gcp-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 (Debian package) - update to 6.12.100-1
linux (Ubuntu package) - addressed in versions 7.0.0-31.31, 7.0.0-31.31.1, 7.0.0-31.31~24.04.1, 7.0.0-1006.7, 7.0.0-1011.11~24.04.1, 7.0.0-1012.12, 7.0.0-1012.12~24.04.1
linux-gcp-7.0 (Ubuntu package) - update to 7.0.0-1011.11~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1013.13

• https://git.kernel.org/stable/c/477145860dba4c30f0b4e36f02f4c5291c1c888b
• https://git.kernel.org/stable/c/6bea2f8becdb20d34378493c3b77a9b9cf8c6cfa
• https://git.kernel.org/stable/c/d4f4d61715d1061ba83b88196a3605662be30750
• https://git.kernel.org/stable/c/dfaef40d8a1533940fc1af788d70fce07362b4ce
• https://git.kernel.org/stable/c/e8042f6e1d7befb2fb6b10a75918642bcd0acf9a

• Use-after-free in Linux kernel hyp nvhe
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux
• Ubuntu update for linux-gcp-7.0