CVE-2026-89921: Linux

EPSS: 0.2% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: KVM: s390: Zero initialize data structures for inject_pfault_token __kvm_inject_pfault_token() only sets .type and .u.ext.ext_params2 of the on-stack struct kvm_s390_irq but the full ext substructure is copied into the cpu local variable on inject. ext_params and pad contain stale stack values. Interrupt delivery only uses ext_params2, so nothing leaks to the guest, but a host user can use the migration ioctls to get to the data. Fix by zero-initializing the irq struct. Do the same for the inti data structure.

Affected products

• Linux Linux: from 3.19, before 6.12.112 (fixed in 6.12.112); from 6.13, before 6.18.52 (fixed in 6.18.52); from 6.19, before 7.2.5 (fixed in 7.2.5)

Published 2026-09-16. Last modified 2026-10-03.