CVE-2026-79603

Xen hypervisor x86 PV (para-virtualized) guests can free memory pages while retaining a stale TLB entry pointing to them. Xen issues a TLB flush only when a freed page is re-used , not at the time of freeing. Because the page can be scrubbed (zeroed or reassigned) before that TLB flush occurs, a ...

CVE-2026-79603 Unconditionally do TLB flushing ahead of page scrubbing

x86 PV guests can free memory pages while still keeping a stale TLB entry pointing to them. A TLB flush is only issued by Xen if needed when the page is re-used. Since it's possible for the page to be scrubbed ahead of the TLB flush, there's a window where a PV guest can modify an already scrubbe...

Unconditionally do TLB flushing ahead of page scrubbing

ISSUE DESCRIPTION x86 PV guests can free memory pages while still keeping a stale TLB entry pointing to them. A TLB flush is only issued by Xen if needed when the page is re-used. Since it's possible for the page to be scrubbed ahead of the TLB flush, there's a window where a PV guest can modify ...