CVE-2025-40223Public exploit

Kernel crash via duplicate MOST USB cleanup

Published Dec 4, 2025 · Updated May 11, 2026

Use-after-free in the Linux MOST USB driver allows local users to crash affected kernels from 5.9 during USB device disconnection. hdm_disconnect() unregisters the interface, then frees mdev-owned allocations and drops redundant device references after release_mdev() can already have released them. Triggering the MOST USB disconnect path is required; the demonstrated consequence is a kernel memory-safety fault and crash.

CVSS severity5.5
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

Use-after-free in the Linux MOST USB driver allows local users to crash affected kernels from 5.9 during USB device disconnection. hdm_disconnect() unregisters the interface, then frees mdev-owned allocations and drops redundant device references after release_mdev() can already have released them. Triggering the MOST USB disconnect path is required; the demonstrated consequence is a kernel memory-safety fault and crash.

The record

CVE
CVE-2025-40223
Published
Dec 4, 2025
Updated
May 11, 2026
Vendor
The Linux Kernel Organization
Product
Linux
Classifications
T1499.004
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Dec 4, 2025CVE publishedPublication date reported by the CVE source.
  2. May 11, 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=5.9
  2. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <33daf469f5294b9d07c4fc98216cace9f4f34cc6
  3. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6
  4. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <4b1270902609ef0d935ed2faa2ea6d122bd148f5
  5. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <578eb18cd111addec94c43f61cd4b4429e454809
  6. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831
  7. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <72427dc6f87523995f4e6ae35a948bb2992cabce
  8. Affected versionversion=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <f93a84ffb884d761a9d4e869ba29c238711e81f1

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

The Linux Kernel Organization · Linuxversion=5.9; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <33daf469f5294b9d07c4fc98216cace9f4f34cc6; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <4b1270902609ef0d935ed2faa2ea6d122bd148f5; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <578eb18cd111addec94c43f61cd4b4429e454809; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <72427dc6f87523995f4e6ae35a948bb2992cabce; version=97a6f772f36b7f52bcfa56a581bbd2470cffe23d <f93a84ffb884d761a9d4e869ba29c238711e81f1

Published CVSS scores

5.5SUSECVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

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

Weakness, pattern, technique

T1499.004Application or System Exploitation

Public exploit references

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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