CVE-2026-74387

Local kernel crash via unsynchronized MIDI teardown

Published Aug 15, 2026 · Updated Aug 15, 2026

Use-after-free in the ALSA sequencer MIDI layer in Linux allows local users to crash the kernel during concurrent output teardown. The event_process_midi() path borrows output_rfile.output without synchronizing with midisynth_unuse(), which can free substream->runtime before snd_rawmidi_kernel_write1() pins it. Triggering the race requires local ALSA sequencer MIDI access during the final output close; the reproduced result is a NULL dereference or stale-runtime access, with no demonstrated code execution.

CVSS severity5.3
Medium
EPSS probability0.13%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Use-after-free in the ALSA sequencer MIDI layer in Linux allows local users to crash the kernel during concurrent output teardown. The event_process_midi() path borrows output_rfile.output without synchronizing with midisynth_unuse(), which can free substream->runtime before snd_rawmidi_kernel_write1() pins it. Triggering the race requires local ALSA sequencer MIDI access during the final output close; the reproduced result is a NULL dereference or stale-runtime access, with no demonstrated code execution.

The record

CVE
CVE-2026-74387
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Aug 15, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 15, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <11165fe2c5ea0516debe486d91df67abbe36905e
  2. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <718f6a56b40875f19e6915799044a02df9abfd52
  3. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <936641af564c3d92721704b781e36aaf223efdd2
  4. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d6fd2afb137f52bf00c5210cc44d08ed54dcffb4
  5. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ef7607ab1c8adc6258fb1b27d08e26aecdc18a58
  6. Affected versionversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f5d470b808bc01f70978e22e595c6f7768313406
  7. Affected versionversion=2.6.12

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <11165fe2c5ea0516debe486d91df67abbe36905e; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <718f6a56b40875f19e6915799044a02df9abfd52; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <936641af564c3d92721704b781e36aaf223efdd2; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <d6fd2afb137f52bf00c5210cc44d08ed54dcffb4; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <ef7607ab1c8adc6258fb1b27d08e26aecdc18a58; version=1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 <f5d470b808bc01f70978e22e595c6f7768313406; version=2.6.12

Published CVSS scores

5.3Amazon LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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