CVE-2026-89959 (CVSS 8.8)

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

EPSS — Exploit Prediction

0.0018

Probability of exploitation

0.07%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

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. The EPSS score is 0.0018, placing it in the 0th percentile for exploitation probability.

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.

CVE-2026-89959