Linux Kernel Vulnerability in ALSA Dummy Sequencer Event Handling

CVE-2026-53241

What is CVE-2026-53241?

A vulnerability in the Linux kernel's ALSA subsystem affects the dummy sequencer's event handling. This issue arises when an incoming UMP event is copied into a smaller legacy stack temporary, leading to a stack overread. Instead of supporting the full UMP packet size, the system incorrectly processes the event while retaining the UMP flag. If not resolved, this vulnerability may allow the delivery of larger-than-expected packets, potentially resulting in unintended memory access and stability issues. The fixed implementation leverages an existing union to safely copy event data while preserving compatibility with legacy event handling.

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