Incorrect calculation in Linux kernel - CVE-2026-89959
Published: September 17, 2026
Vulnerability details
The vulnerability allows a local user to compromise the confidentiality, integrity, and availability of a KVM guest.
The vulnerability exists due to an incorrect bitmap operation in vfio_ap_mdev_cfg_remove when removing control domains from a mediated device. A local user can trigger control-domain removal to compromise the confidentiality, integrity, and availability of a KVM guest.
Affected software
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)
How to mitigate CVE-2026-89959
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
External References
- https://git.kernel.org/stable/c/02e72909453dee2f8a09f78819f9a9cb902dfbdc
- https://git.kernel.org/stable/c/12871a4269f139221c9fde9ea3eb69c9228f59d4
- https://git.kernel.org/stable/c/2ff68bf414de167bc138e6e211ee1ad3ab3c5052
- https://git.kernel.org/stable/c/4bffadde7fc49b00493fb78c6376f958998d4b8c
- https://git.kernel.org/stable/c/6b8a02e216f6b520cc029e43ddc83956605135d5
- https://git.kernel.org/stable/c/f7d66afc34bc6e833c8ebe56973afec35f473bc1