CVE-2025-39757

In the Linux kernel, the following vulnerability has been resolved:

ALSA: usb-audio: Validate UAC3 cluster segment descriptors

UAC3 class segment descriptors need to be verified whether their sizes match with the declared lengths and whether they fit with the allocated buffer sizes, too. Otherwise malicious firmware may lead to the unexpected OOB accesses.

This vulnerability is rated as Moderate severity rather than Low because an out-of-bounds memory access in kernel space can compromise system stability, though exposure is restricted by requiring physical insertion of a crafted USB device or the ability to attach virtualized hardware. In typical Red Hat Enterprise Linux environments, the sound subsystem automatically loads the relevant driver upon device connection. An attacker with access to attach such hardware could trigger this flaw using malformed audio descriptors, resulting in a kernel crash and denial of service.

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.