CVE-2026-72412

A flaw was found in the Linux kernel's memory management for s390 systems. An internal flag, intended to mark guest memory pages for discard after unmapping by the Kernel-based Virtual Machine (KVM), was not consistently cleared when those pages were subsequently reused. This improper handling could cause actively used guest memory to be prematurely discarded. The most significant consequence is data corruption within guest virtual machines.

Red Hat rates this flaw as a Moderate severity impact because potential exploitation requires local access within an IBM Z (s390x) virtualized environment and is limited to guest memory corruption or denial of service rather than host compromise. The underlying problem is restricted to KVM page table flag handling under specific unmapping conditions on the s390x platform. In addition, supported Red Hat Enterprise Linux releases do not include the vulnerable upstream changes, leaving typical production workloads unaffected.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.