CVE-2026-89920

7.8 HIGH

Published 2026-09-16 · Updated 2026-09-16

AI risk analysis

Summary: This vulnerability in the Linux kernel's KVM s390 implementation allows for potential memory corruption by improperly handling machine checks related to the channel subsystem. It matters because it could lead to arbitrary code execution if exploited.
Exploitability: Exploitation is considered difficult as it requires specific conditions and knowledge of the affected kernel version. Precondition is the presence of a vulnerable KVM s390 environment.
Blast radius: If exploited, the impact could be severe, potentially leading to full system compromise and arbitrary code execution on the host system.
Detection: No reliable host or network indicator is derivable from the published description.
Prioritized remediation: Upgrade to the fixed version 5.10.147 or later.

kernels390memory-corruptionvulnerability

Analysis generated locally by qwen2.5:7b-instruct (no data left the box). AI-assisted — verify against primary sources before acting.

NVD description

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Fix memory corruption by not reinjecting CK machine checks Channel-subsystem damage machine checks are for the host channel subsystem. The guest channel subsystem is emulated in the userspace VMM. There is no point in forwarding such machine checks into the guest. This also simplifies the machine check reinjection and avoids kfree of a stack variable as reported by sashiko. There might be still machine checks that have the ck bit set with another bit (like instruction damage), mask out the CK bit in s390_backup_mcck_info(), like the CP and ED bits already are.

CVSS vector

CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:H/A:H

References

Data: NVD (public domain). Analysis: local $0 model. Defensive use only.