CVE-2026-98283
Description
A flaw was found in the Linux kernel's KVM (Kernel-based Virtual Machine) subsystem for PowerPC. A race condition occurs during memory management emulation when nested guest virtual machine structures are freed while still in use by another virtual processor. A malicious guest virtual machine can exploit this timing discrepancy to trigger a use-after-free condition where the host kernel accesses deallocated memory. This flaw primarily allows an attacker to cause a Denial of Service (DoS) through a host system crash, and may potentially lead to arbitrary code execution.
Statement
This vulnerability is rated as having Moderate impact because it is restricted to PowerPC Book3S architectures running nested KVM virtualization, requiring an attacker with existing privileges inside a virtual guest to win a race condition. Systems that do not run nested virtualization on PowerPC Book3S hardware are unaffected by this issue. Successful exploitation could allow a malicious guest to crash the host kernel or potentially escalate privileges, though the specific architecture and concurrency requirements limit the overall exposure across standard enterprise environments.
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 | 7 | N/A | 8.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | High | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Changed |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
If the expired pointer is used in a read operation, an attacker might be able to control data read in by the application.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
If the expired pointer references a memory location that is not accessible to the product, or points to a location that is "malformed" (such as NULL) or larger than expected by a read or write operation, then a crash may occur.
Integrity,Confidentiality,Availability
Technical Impact: Execute Unauthorized Code or Commands
If the expired pointer is used in a function call, or points to unexpected data in a write operation, then code execution may be possible.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
