CVE-2026-80921

In the Linux kernel, the following vulnerability has been resolved:

KVM: s390: vsie: zero stale crypto bits

When shadowing crypto access bits from a format0 apcb (crycb 0 or 1),
the bits 64..255 are unchanged from whatever is in the vsie page in the
crycb and thus in the apcb. This gives a nested guest potential access
to a device no longer available. Zero out the remaining bits.