CVE-2026-89959
HIGH
Published Sep 16, 2026
Modified Sep 16, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove The vfio_ap_config_remove function uses the bitmap_andnot function to clear bits from the matrix_mdev->matrix.adm bitmap (specifies the control domains assigned to the mdev). This prevents the explicitly unplugged control domains from being removed the KVM guest. The bitmap_and function is used instead.
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CVSS v3.1 Score
8.8
HIGH
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
References
Other 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
Frequently Asked Questions
What is CVE-2026-89959? +
In the Linux kernel, the following vulnerability has been resolved:
s390/vfio-ap: Fix control domain removal in vfio_ap_mdev_cfg_remove
The vfio_ap_config_remove function uses the bitmap_andnot function to clear
bits from the matrix_mdev->matrix.adm bitmap (specifies the control domains
assigned to the mdev). This prevents the explicitly unplugged control
domains from being removed the KVM guest. The bitmap_and function is used
instead. It has a CVSS v3.1 base score of 8.8 (HIGH).
How severe is CVE-2026-89959? +
CVE-2026-89959 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching.
How do I check if I'm vulnerable to CVE-2026-89959? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.