---
id: CVE-2026-53241
title: 'ALSA: seq: dummy: fix UMP event stack overread'
summary: |-
  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 s…
severity: none
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 <
    a7ef78a2c536242ccb7a4429da01580b2409bb24
  - >-
    Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 <
    6671a46144f880c5a167930ebb14c12f3d059fe9
  - >-
    Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 <
    6676b6063440561db600494049ce7ffb695c8cc4
  - >-
    Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 <
    2b5ff4db5d7aa5b981d966df02e687f79ad7b311
  - Linux 6.10
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-11-06T16:23:37.290661Z'
published: '2026-06-25'
updated: '2026-11-06'
sourceUpdated: '2026-11-06T16:24:08.727Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-53241'
references:
  - url: 'https://git.kernel.org/stable/c/a7ef78a2c536242ccb7a4429da01580b2409bb24'
  - url: 'https://git.kernel.org/stable/c/6671a46144f880c5a167930ebb14c12f3d059fe9'
  - url: 'https://git.kernel.org/stable/c/6676b6063440561db600494049ce7ffb695c8cc4'
  - url: 'https://git.kernel.org/stable/c/2b5ff4db5d7aa5b981d966df02e687f79ad7b311'
tags:
  - cve.org
epss: 0.00162
epssPercentile: 0.05382
ingestedAt: '2026-11-06T16:57:43.269Z'
---

## Overview

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.

## Affected

- `Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 < a7ef78a2c536242ccb7a4429da01580b2409bb24`
- `Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 < 6671a46144f880c5a167930ebb14c12f3d059fe9`
- `Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 < 6676b6063440561db600494049ce7ffb695c8cc4`
- `Linux >= 32cb23a0f911317cdb5030035e49a204aa86fef5 < 2b5ff4db5d7aa5b981d966df02e687f79ad7b311`
- `Linux 6.10`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.