CVE-2026-74499

Kernel memory corruption via wrapped SysEx fill bound

Published Aug 15, 2026 · Updated Aug 15, 2026

Heap out-of-bounds write in Linux kernel ALSA USB MIDI allows physically proximate attackers to corrupt kernel memory through a USB device. In snd_usbmidi_akai_output(), a negative signed fill bound is converted to a large unsigned value, causing repeated SysEx writes beyond the URB buffer. Exploitation requires a device advertising a tiny bulk-OUT endpoint and a process write to its created MIDI node.

CVSS severity7.0
High
EPSS probability0.18%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Heap out-of-bounds write in Linux kernel ALSA USB MIDI allows physically proximate attackers to corrupt kernel memory through a USB device. In snd_usbmidi_akai_output(), a negative signed fill bound is converted to a large unsigned value, causing repeated SysEx writes beyond the URB buffer. Exploitation requires a device advertising a tiny bulk-OUT endpoint and a process write to its created MIDI node.

The record

CVE
CVE-2026-74499
Published
Aug 15, 2026
Updated
Aug 15, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1200
Attack vector
physical
Privileges
Unavailable

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=2.6.35
  2. Affected versionversion=4434ade8c9334a3ab975d8993de456f06841899e <0970274613fb463d376211450cab066d34ebfe6a
  3. Affected versionversion=4434ade8c9334a3ab975d8993de456f06841899e <29a4c29943631301e85f5e9d10f25741bd78e7ba
  4. Affected versionversion=4434ade8c9334a3ab975d8993de456f06841899e <2b7a0f330dd90dd1a7657cec0db019ee1efa4372
  5. Affected versionversion=4434ade8c9334a3ab975d8993de456f06841899e <9b22a5c8310b0d55d04f5f0159b913a2fb8b444f
  6. Affected versionversion=4434ade8c9334a3ab975d8993de456f06841899e <b5305a0d0bb8e90a6fc9f88270d5f6c9b8c40081

What conditions does exploitation require?

Attack vectorphysical
Required privilegesUnavailable in this record.

What is affected?

The Linux Kernel Organization · Linuxversion=2.6.35; version=4434ade8c9334a3ab975d8993de456f06841899e <0970274613fb463d376211450cab066d34ebfe6a; version=4434ade8c9334a3ab975d8993de456f06841899e <29a4c29943631301e85f5e9d10f25741bd78e7ba; version=4434ade8c9334a3ab975d8993de456f06841899e <2b7a0f330dd90dd1a7657cec0db019ee1efa4372; version=4434ade8c9334a3ab975d8993de456f06841899e <9b22a5c8310b0d55d04f5f0159b913a2fb8b444f; version=4434ade8c9334a3ab975d8993de456f06841899e <b5305a0d0bb8e90a6fc9f88270d5f6c9b8c40081

Published CVSS scores

6.6Amazon LinuxCVSS:3.1/AV:P/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
7.0Oracle LinuxCVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/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.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

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

Weakness, pattern, technique

T1200Hardware Additions

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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