CVE-2026-89919 and is rated High severity with a CVSS score of 7.8. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.
CISA KEVNot listedBased on the latest collected catalog
EPSS0.2%Estimated 30-day exploitation probability
Ransomware useNot markedCISA KEV ransomware field
Threat actors0Source-linked actor relationships
Overview
What is CVE-2026-89919?
In the Linux kernel, the following vulnerability has been resolved:
KVM: s390: keyop: use mmu_lock to read gmap->asce
Every other dat_* consumer in this file (kvm_s390_get_skeys, set_skeys, get_cmma_bits, set_cmma_bits, MEM_CLR_CMMA, kvm_s390_fixup_prefix, kvm_test_age_gfn, kvm_age_gfn) reads kvm->arch.gmap->asce *inside* the mmu_lock read-side. keyop is the only outlier.
gmap->asce is mutated under write_lock(mmu_lock) by gmap_set_limit() and keyop might use a stale asce value for walking as KVM_S390_KEYOP and KVM_S390_VM_MEM_LIMIT_SIZE can run concurrently. This can result in memory corruption.