CVE-2026-53241

Technical Description

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

ALSA: seq: dummy: fix UMP event stack overread

The dummy sequencer port forwards events by copying an incoming

struct snd_seq_event into a stack temporary, rewriting source and

destination, and dispatching the temporary to subscribers. That legacy

event storage is smaller than struct snd_seq_ump_event.

When a UMP event reaches the dummy client, the copy leaves the UMP flag

set but only provides legacy-sized stack storage. The subscriber

delivery path then uses snd_seq_event_packet_size() and copies a

UMP-sized packet from that stack object, reading past the end of the

temporary.

Use the existing union __snd_seq_event storage and copy the packet size

reported for the incoming event before rewriting the common routing

fields. This preserves the full UMP packet for UMP events while keeping

legacy event handling unchanged.

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References