Out-of-Bounds Write Vulnerability in Linux Kernel ALSA USB-Audio

CVE-2026-43279

What is CVE-2026-43279?

A vulnerability has been identified in the ALSA USB-audio component of the Linux kernel. This issue arises when handling playback URB packets in implicit framebuffer mode. The system incorrectly assumes that incoming data packets conform to the expected buffer size. In scenarios where the setup between capture and playback streams differs, such as limitations imposed by USB core maximum packet size, this mismatch can lead to out-of-bounds writes, potentially resulting in a crash. To mitigate this, a sanity check has been implemented at the prepare_silent_urb() function to ensure the transfer buffer size is validated before proceeding with data copying. However, it's important to note that this fix does not resolve the underlying cause of the playback errors.

References