CVE-2021-47096

Raw MIDI operation failure via uninitialized protocol state

Published Mar 4, 2024 · Updated May 23, 2026

Uninitialized-state use in Linux 5.14.10 through 5.15 allows local users to disrupt ALSA raw MIDI device initialization. snd_rawmidi_open allocates snd_rawmidi_file with kmalloc but leaves user_pversion unset, so the parameter ioctl compares an indeterminate value and selects the wrong compatibility handling. Access to a raw MIDI device is required; observed consequences include invalid-argument failures, aborted audio applications, and failure to initialize the device.

CVSS severity4.0
Medium
EPSS probability0.21%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Uninitialized-state use in Linux 5.14.10 through 5.15 allows local users to disrupt ALSA raw MIDI device initialization. snd_rawmidi_open allocates snd_rawmidi_file with kmalloc but leaves user_pversion unset, so the parameter ioctl compares an indeterminate value and selects the wrong compatibility handling. Access to a raw MIDI device is required; observed consequences include invalid-argument failures, aborted audio applications, and failure to initialize the device.

The record

CVE
CVE-2021-47096
Published
Mar 4, 2024
Updated
May 23, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 4, 2024CVE publishedPublication date reported by the CVE source.
  2. May 23, 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=09d23174402da0f10e98da2c61bb5ac8e7d79fdd <39a8fc4971a00d22536aeb7d446ee4a97810611b
  2. Affected versionversion=09d23174402da0f10e98da2c61bb5ac8e7d79fdd <b398fcbe4de1e1100867fdb6f447c6fbc8fe7085
  3. Affected versionversion=12d50801497235956fb3760be8530f4e44e4ce67
  4. Affected versionversion=5.14.10 <5.15
  5. Affected versionversion=5.15

What conditions does exploitation require?

Attack vectorlocal
Required privilegesunauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=09d23174402da0f10e98da2c61bb5ac8e7d79fdd <39a8fc4971a00d22536aeb7d446ee4a97810611b; version=09d23174402da0f10e98da2c61bb5ac8e7d79fdd <b398fcbe4de1e1100867fdb6f447c6fbc8fe7085; version=12d50801497235956fb3760be8530f4e44e4ce67; version=5.14.10 <5.15; version=5.15

Published CVSS scores

4.0CISA-ADPCVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

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 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

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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