CVE-2026-68454
Description
A flaw was found in the KVM (Kernel-based Virtual Machine) subsystem of the Linux kernel, affecting the s390 PCI implementation. When a guest operating system registers interrupt requests (IRQs) without a specific summary bit, the system incorrectly stores an invalid memory address. This improper handling of memory addresses can lead to system instability, potentially resulting in a denial of service for the host system.
Statement
This vulnerability is rated as Moderate because exploitation is restricted to IBM Z (s390x) environments hosting KVM virtual machines with PCI device passthrough, requiring access from within an active guest. Deployments on other hardware architectures or s390x systems not utilizing KVM virtualization are unaffected. While a guest triggering this condition can induce a host kernel crash resulting in a denial of service, the flaw does not facilitate arbitrary code execution or data leakage across guest boundaries.
Mitigation
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
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 | 8.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| 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:L/UI:N/S:C/C:H/I:H/A:H
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