CVE-2026-63904

A flaw was found in the Linux kernel's USB Test and Measurement Class (USBTMC) driver. This vulnerability occurs because the driver does not properly verify the size of incoming notification messages, specifically failing to ensure that required two-byte headers are present. An attacker could exploit this by sending malformed USBTMC messages, potentially leading to an out-of-bounds read. This could result in a system crash (Denial of Service) or the disclosure of sensitive information.

This vulnerability is evaluated as Moderate because successful exploitation requires local access or the connection of a specialized, malformed USB device, limiting the attack scope primarily to a local system crash. The USB Test and Measurement Class driver is not loaded by default on typical enterprise systems and is only invoked when compatible instrumentation hardware is plugged in. Deployments that do not interface with USB test equipment or that restrict untrusted local device emulation are not exposed to this issue.

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.