CVE-2026-63942

A flaw was found in the Linux kernel's parallel port (parport) subsystem. This vulnerability is caused by a race condition where parallel port devices are registered before they are fully initialized. This allows client drivers to interact with uninitialized or unstable ports, which can lead to a system crash. A local attacker could exploit this by repeatedly loading and unloading parallel port modules, resulting in a Denial of Service (DoS).

This vulnerability is rated as Moderate impact for Red Hat Enterprise Linux because exploitation is limited to a local denial of service without compromising confidentiality or data integrity, and it requires precise race timing during parallel port driver registration. In typical enterprise and cloud environments, physical parallel ports are rarely present or utilized, which substantially minimizes real-world exposure. Furthermore, triggering the condition intentionally demands privileged access or specific hardware discovery events during system initialization.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

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.