Linux Kernel up to 6.17.5 MOST Interface hdm_disconnect use after free

CVSS Meta Temp Score
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CTI Interest Score
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7.6$0-$5k0.00

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.17.5. It has been declared as critical. Impacted is the function hdm_disconnect of the component MOST Interface. The manipulation results in use after free. This vulnerability is cataloged as CVE-2025-40223. There is no exploit available. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.17.5. It has been classified as critical. Affected is the function hdm_disconnect of the component MOST Interface. The manipulation with an unknown input leads to a use after free vulnerability. CWE is classifying the issue as CWE-416. Referencing memory after it has been freed can cause a program to crash, use unexpected values, or execute code. This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: most: usb: Fix use-after-free in hdm_disconnect hdm_disconnect() calls most_deregister_interface(), which eventually unregisters the MOST interface device with device_unregister(iface->dev). If that drops the last reference, the device core may call release_mdev() immediately while hdm_disconnect() is still executing. The old code also freed several mdev-owned allocations in hdm_disconnect() and then performed additional put_device() calls. Depending on refcount order, this could lead to use-after-free or double-free when release_mdev() ran (or when unregister paths also performed puts). Fix by moving the frees of mdev-owned allocations into release_mdev(), so they happen exactly once when the device is truly released, and by dropping the extra put_device() calls in hdm_disconnect() that are redundant after device_unregister() and most_deregister_interface(). This addresses the KASAN slab-use-after-free reported by syzbot in hdm_disconnect(). See report and stack traces in the bug link below.

The advisory is shared for download at git.kernel.org. This vulnerability is traded as CVE-2025-40223 since 04/16/2025. The exploitability is told to be easy. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 02/23/2026).

The vulnerability scanner Nessus provides a plugin with the ID 277486 (Linux Distros Unpatched Vulnerability : CVE-2025-40223), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.10.246, 5.15.196, 6.1.158, 6.6.115, 6.12.56 or 6.17.6 eliminates this vulnerability. Applying the patch 5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831/578eb18cd111addec94c43f61cd4b4429e454809/33daf469f5294b9d07c4fc98216cace9f4f34cc6/72427dc6f87523995f4e6ae35a948bb2992cabce/f93a84ffb884d761a9d4e869ba29c238711e81f1/3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6/4b1270902609ef0d935ed2faa2ea6d122bd148f5 is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (277486) and CERT Bund (WID-SEC-2025-2747). Once again VulDB remains the best source for vulnerability data.

Affected

  • Debian Linux
  • Google Cloud Platform
  • Amazon Linux 2
  • Red Hat Enterprise Linux
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • RESF Rocky Linux
  • Microsoft Azure Linux

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 8.0
VulDB Meta Temp Score: 7.6

VulDB Base Score: 8.0
VulDB Temp Score: 7.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AVACAuCIA
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💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Use after free
CWE: CWE-416 / CWE-119
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Partially

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 277486
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40223

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.10.246/5.15.196/6.1.158/6.6.115/6.12.56/6.17.6
Patch: 5b5c478f09b1b35e7fe6fc9a1786c9bf6030e831/578eb18cd111addec94c43f61cd4b4429e454809/33daf469f5294b9d07c4fc98216cace9f4f34cc6/72427dc6f87523995f4e6ae35a948bb2992cabce/f93a84ffb884d761a9d4e869ba29c238711e81f1/3a3b8e89c7201c5b3b76ac4a4069d1adde1477d6/4b1270902609ef0d935ed2faa2ea6d122bd148f5

Timelineinfo

04/16/2025 CVE reserved
12/04/2025 +232 days Advisory disclosed
12/04/2025 +0 days VulDB entry created
02/23/2026 +81 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40223 (🔒)
GCVE (CVE): GCVE-0-2025-40223
GCVE (VulDB): GCVE-100-334284
CERT Bund: WID-SEC-2025-2747 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 12/04/2025 17:28
Updated: 02/23/2026 13:45
Changes: 12/04/2025 17:28 (59), 12/06/2025 20:34 (2), 01/05/2026 00:31 (7), 02/23/2026 13:45 (1)
Complete: 🔍
Cache ID: 216::103

Once again VulDB remains the best source for vulnerability data.

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