Use-after-free in Linux kernel - CVE-2026-74387

CSH
CYBERSECURITY HELP
Sign In REGISTER
 
Main Vulnerability Database Vulnerabilities #VU142761

Use-after-free in Linux kernel - CVE-2026-74387

Published: August 15, 2026


Vulnerability identifier: #VU142761
CSH Severity: Low
CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2026-74387
CWE-ID: CWE-416
Exploitation vector: Local access
Exploit availability: No public exploit available

Vulnerability details

The vulnerability allows a local user to cause a denial of service or execute arbitrary code.

The vulnerability exists due to use-after-free in the ALSA sequencer MIDI output handling in sound/core/seq/seq_midi.c when processing MIDI sequencer events during concurrent output teardown. A local user can trigger concurrent event processing and output teardown to cause a denial of service or execute arbitrary code.

The issue occurs because the event_input path can keep using a stale substream or runtime after the last unuse path releases the rawmidi file.


Affected software

Linux kernel
Ubuntu
linux-gcp-7.0 (Ubuntu package)
linux-azure-7.0 (Ubuntu package)

How to mitigate CVE-2026-74387

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux-gcp-7.0 (Ubuntu package) - addressed in versions 7.0.0-38.38~24.04.4, 7.0.0-1013.13~24.04.1, 7.0.0-1014.14~24.04.1
linux-azure-7.0 (Ubuntu package) - addressed in versions 7.0.0-1016.16~24.04.1, 7.0.0-1017.17~24.04.1

External References

Related Security Bulletins