CVE-2026-72412
Description
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.
Statement
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.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | 9.3 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | None |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Changed |
| Confidentiality | None | N/A | High |
| Integrity Impact | None | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
