CVE-2026-23318

A flaw was found in the Linux kernel's ALSA (Advanced Linux Sound Architecture) USB audio driver. A malicious USB Audio Class 3 (UAC3) device could exploit an incorrect protocol version used for UAC3 header validation. This error causes the device's header descriptors to bypass validation, allowing a truncated UAC3 header to trigger out-of-bounds reads when the driver processes unvalidated descriptor fields.

This flaw affects systems with USB audio devices using UAC3 (USB Audio Class 3). A copy-paste error caused UAC3 header validation to use UAC_VERSION_2 instead of UAC_VERSION_3, completely bypassing validation for UAC3 devices. A malicious USB device could provide truncated descriptors to cause OOB reads. Physical access to connect the USB device is required.

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.

To mitigate this issue, prevent the snd_usb_audio module from being loaded. See https://access.redhat.com/solutions/41278 for instructions.