CVE-2026-98563
Description
A flaw was found in the Linux kernel's phylink component. When an error occurs during Ethernet physical layer (PHY) device initialization, the kernel prematurely stores a reference to the device before setup finishes. If the bringup operation fails, the device is detached and freed, but the kernel retains a stale pointer. A local user with administrative privileges or network hardware events triggering connection retries can cause the kernel to access this freed memory, leading to memory corruption or a Denial of Service (DoS) via a system crash.
Statement
This vulnerability is rated as having Moderate impact because exploitation requires either local administrative access or specific physical hardware failure events during PHY link initialization. The affected phylink subsystem is primarily utilized by specialized network adapters and embedded architectures rather than standard enterprise network controllers. Furthermore, the consequence is limited to a local denial of service via a kernel crash caused by dereferencing stale memory upon connection retry.
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 | 4.1 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | High | N/A | N/A |
| Privileges Required | High | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H
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