CVE-2026-90021Hinoki check available

Kernel warning via uninitialized USB MIDI work item

Published Sep 16, 2026 · Updated Sep 16, 2026

Improper initialization in the Linux kernel USB MIDI gadget driver allows local privileged users to trigger a kernel warning. The f_midi_alloc function leaves its work item uninitialized when binding never occurs, and f_midi_free later passes that item to __flush_work with a null function pointer. Reaching the path requires privileged configfs manipulation; upstream testing reports a warning but no denial of service or exploitability.

CVSS severityUnavailable
Unscored
EPSS probabilityUnavailable
No score available in this record
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Improper initialization in the Linux kernel USB MIDI gadget driver allows local privileged users to trigger a kernel warning. The f_midi_alloc function leaves its work item uninitialized when binding never occurs, and f_midi_free later passes that item to __flush_work with a null function pointer. Reaching the path requires privileged configfs manipulation; upstream testing reports a warning but no denial of service or exploitability.

The record

CVE
CVE-2026-90021
Published
Sep 16, 2026
Updated
Sep 16, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
Unavailable
Attack vector
local
Privileges
admin

Timeline

How it unfolded

  1. Sep 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 16, 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=3635523e9b96213969693c320302d536774d8e9b
  2. Affected versionversion=5.10.235 <5.11
  3. Affected versionversion=5.12
  4. Affected versionversion=5.4.291 <5.5
  5. Affected versionversion=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <02ac76f27db23ef652358458c272d9d2d6f51167
  6. Affected versionversion=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <3d8b11255e632170f32f1925bfcaf96331f36317
  7. Affected versionversion=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <7e07d3e4c389217d7d7171d80edf2e23ac70f1ea
  8. Affected versionversion=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <858576de6b2f5166b08dae803f0fd0766dcb3002
  9. Affected versionversion=89019ab7a64fcdf98a2ba7799e5c6aff58d4a05d

What conditions does exploitation require?

Attack vectorlocal
Required privilegesadmin

What is affected?

The Linux Kernel Organization · Linuxversion=3635523e9b96213969693c320302d536774d8e9b; version=5.10.235 <5.11; version=5.12; version=5.4.291 <5.5; version=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <02ac76f27db23ef652358458c272d9d2d6f51167; version=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <3d8b11255e632170f32f1925bfcaf96331f36317; version=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <7e07d3e4c389217d7d7171d80edf2e23ac70f1ea; version=8653d71ce3763aedcf3d2331f59beda3fecd79e4 <858576de6b2f5166b08dae803f0fd0766dcb3002; version=89019ab7a64fcdf98a2ba7799e5c6aff58d4a05d

Published CVSS scores

No CVSS assessment is available in this record.

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
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

No sourced classifications are available.

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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