Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1 f_midi f_midi_alloc initialization

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.5	$0-$5k	0.00-

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1. It has been rated as critical. Affected by this vulnerability is the function f_midi_alloc of the component f_midi. Performing a manipulation results in initialization. This vulnerability is reported as CVE-2026-90021. The attack is possible to be carried out remotely. No exploit exists. Upgrading the affected component is advised.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.12.109/6.18.50/7.2.4/7.3-rc1. This affects the function f_midi_alloc of the component f_midi. The manipulation with an unknown input leads to a initialization vulnerability. CWE is classifying the issue as CWE-665. The product does not initialize or incorrectly initializes a resource, which might leave the resource in an unexpected state when it is accessed or used. This is going to have an impact on availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: f_midi: initialize work in f_midi_alloc() f_midi_alloc initializes free_ref to 1 and it can only be incremented when a sound card is registered via f_midi_register_card(). f_midi_register_card() is only called in f_midi_bind() which actually performs INIT_WORK. If f_midi_bind() is never run, work is not initialized and the if condition in f_midi_free becomes true, this results in a warning later in __flush_work as work->func = 0. Fix this by moving INIT_WORK from f_midi_bind() to f_midi_alloc().

It is possible to read the advisory at git.kernel.org. This vulnerability is uniquely identified as CVE-2026-90021 since 09/11/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. It demands that the victim is doing some kind of user interaction. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 09/16/2026).

Upgrading to version 6.12.110, 6.18.51, 7.2.5 or 7.3-rc2 eliminates this vulnerability. Applying the patch 3d8b11255e632170f32f1925bfcaf96331f36317/858576de6b2f5166b08dae803f0fd0766dcb3002/7e07d3e4c389217d7d7171d80edf2e23ac70f1ea is able to eliminate this problem. The best possible mitigation is suggested to be upgrading to the latest version.

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.12.109
• 6.18.0
• 6.18.1
• 6.18.2
• 6.18.3
• 6.18.4
• 6.18.5
• 6.18.6
• 6.18.7
• 6.18.8
• 6.18.9
• 6.18.10
• 6.18.11
• 6.18.12
• 6.18.13
• 6.18.14
• 6.18.15
• 6.18.16
• 6.18.17
• 6.18.18
• 6.18.19
• 6.18.20
• 6.18.21
• 6.18.22
• 6.18.23
• 6.18.24
• 6.18.25
• 6.18.26
• 6.18.27
• 6.18.28
• 6.18.29
• 6.18.30
• 6.18.31
• 6.18.32
• 6.18.33
• 6.18.34
• 6.18.35
• 6.18.36
• 6.18.37
• 6.18.38
• 6.18.39
• 6.18.40
• 6.18.41
• 6.18.42
• 6.18.43
• 6.18.44
• 6.18.45
• 6.18.46
• 6.18.47
• 6.18.48
• 6.18.49
• 6.18.50
• 7.2.0
• 7.2.1
• 7.2.2
• 7.2.3
• 7.2.4
• 7.3-rc1

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.7
VulDB Meta Temp Score: 5.5

VulDB Base Score: 5.7
VulDB Temp Score: 5.5
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Initialization
CWE: CWE-665
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 6.12.110/6.18.51/7.2.5/7.3-rc2
Patch: 3d8b11255e632170f32f1925bfcaf96331f36317/858576de6b2f5166b08dae803f0fd0766dcb3002/7e07d3e4c389217d7d7171d80edf2e23ac70f1ea

Timelineinfo

09/11/2026 CVE reserved
09/16/2026 +5 days Advisory disclosed
09/16/2026 +0 days VulDB entry created
09/16/2026 +0 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2026-90021 (🔒)
GCVE (CVE): GCVE-0-2026-90021
GCVE (VulDB): GCVE-100-405867

Entryinfo

Created: 09/16/2026 15:27
Changes: 09/16/2026 15:27 (59)
Complete: 🔍
Cache ID: 216::103

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion

Do you know our Splunk app?

Download it now for free!