CVE-2026-43012
Description
A flaw was found in the Linux kernel's net/mlx5 driver. This vulnerability occurs when the switchdev mode fails to initialize or transition correctly, leading to an improper rollback to legacy mode. During this rollback, the system attempts to unregister an already unregistered uplink network device, which can cause a kernel panic. A local attacker or process could exploit this flaw to trigger a system crash, resulting in a Denial of Service (DoS).
Statement
A Moderate severity flaw exists in the Linux kernel's net/mlx5 driver, affecting systems with Mellanox network adapters. This vulnerability can lead to a kernel panic and system crash if the switchdev mode fails to initialize or transition correctly, causing an improper rollback. Exploitation requires local access to trigger the Denial of Service.
Mitigation
To mitigate this issue, systems not requiring `switchdev` functionality for Mellanox network adapters should be configured to operate in `legacy` mode. This can be done using the `devlink` utility. For example, to set the eswitch mode to legacy for a device named `mlx5_0`:
`# devlink dev eswitch set mlx5_0 mode legacy`
Applying this configuration may require a network service restart or system reboot to ensure the change is fully active.
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 | 5.5 | N/A |
| Attack Vector | Local | Local | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | Low | Low | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | High | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Modify Application Data; Alter Execution Logic
The application could be placed in an insecure state that may allow an attacker to modify sensitive data or allow unintended logic to be executed.
Frequently Asked Questions
Not sure what something means? Check out our Security Glossary.
Want to get errata notifications? Sign up here.
