Use-after-free in Linux kernel - CVE-2026-89960

Vulnerability identifier: #VU150326

CSH Severity: Low

CVSS v4: 8.5 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-89960

CWE-ID: CWE-416

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to compromise confidentiality, integrity, and availability.

The vulnerability exists due to a use-after-free in the s390 VFIO AP mediated-device KVM assignment handling when executing a PQAP instruction in a guest after a failed conflicting mediated-device assignment and subsequent freeing of the mediated device. A local user can trigger a conflicting mediated-device assignment and execute a PQAP instruction in the guest to compromise confidentiality, integrity, and availability.

Linux kernel
Debian Linux
Ubuntu
linux-nvidia-tegra (Ubuntu package)
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)
linux (Debian package)

Install security update from vendor's repository.

linux-nvidia-tegra (Ubuntu package) - update to 6.8.0-1038.42
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
linux (Debian package) - update to 6.12.111-1

• https://git.kernel.org/stable/c/13bfc94eef389bd664ffc67b00184919902c938a
• https://git.kernel.org/stable/c/4400270ec0348d05dc0439d8f0130853ce7f9e20
• https://git.kernel.org/stable/c/6a180adafc2a8a5fbe815985c71b2201e93ab5e1
• https://git.kernel.org/stable/c/eb6cc898501a004c0fa8aab951351d9c959b91cc
• https://git.kernel.org/stable/c/fc069d00a0dbef40042fd681554d48dcd5a1d524

• Use-after-free in Linux kernel s390 crypto driver
• Debian update for linux
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more
• Ubuntu update for linux-nvidia-tegra