CVE-2026-89927 Linux Kernel KVM - Denial of Service

Linux kernel KVM x86 Hyper-V synthetic timer contains an integer overflow in stimer deadline calculation, letting guest or userspace cause CPU livelock and RCU stalls, exploit requires programming timer with large COUNT value.

CVSS base score 7.1 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
EPSS
0.18% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Published
16 September 2026
Updated
15 October 2026

Vendor fix

Update to the latest Linux kernel version containing the fix for this issue.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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