Linux Kernel up to 6.18-rc1 usb-audio try_to_register_card null pointer dereference

CVSS Meta Temp Score
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CTI Interest Score
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5.5$0-$5k0.00

Summaryinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.18-rc1. The affected element is the function try_to_register_card of the component usb-audio. The manipulation results in null pointer dereference. This vulnerability is reported as CVE-2025-40085. No exploit exists. You should upgrade the affected component.

Detailsinfo

A vulnerability, which was classified as critical, was found in Linux Kernel up to 6.18-rc1. Affected is the function try_to_register_card of the component usb-audio. The manipulation with an unknown input leads to a null pointer dereference vulnerability. CWE is classifying the issue as CWE-476. A NULL pointer dereference occurs when the application dereferences a pointer that it expects to be valid, but is NULL, typically causing a crash or exit. This is going to have an impact on availability. CVE summarizes:

In the Linux kernel, the following vulnerability has been resolved: ALSA: usb-audio: Fix NULL pointer deference in try_to_register_card In try_to_register_card(), the return value of usb_ifnum_to_if() is passed directly to usb_interface_claimed() without a NULL check, which will lead to a NULL pointer dereference when creating an invalid USB audio device. Fix this by adding a check to ensure the interface pointer is valid before passing it to usb_interface_claimed().

The advisory is available at git.kernel.org. This vulnerability is traded as CVE-2025-40085 since 04/16/2025. Technical details are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 271973 (Linux Distros Unpatched Vulnerability : CVE-2025-40085), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 5.15.196, 6.1.158, 6.6.114, 6.12.55, 6.17.5 or 6.18-rc2 eliminates this vulnerability. Applying the patch 736159f7b296d7a95f7208eb4799639b1f8b16a0/8d19a7ab28c7b9c207db5c5282afa8cc8595bcdb/576312eb436326b44b7010f4d9ae2b698df075ea/bba7208765d26e5e36b87f21dacc2780b064f41f/8503ac1a62075a085402e42a386b5c627c821a51/28412b489b088fb88dff488305fd4e56bd47f6e4 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 (271973) and CERT Bund (WID-SEC-2025-2441). If you want to get best quality of vulnerability data, you may have to visit VulDB.

Affected

  • Debian Linux
  • Amazon Linux 2
  • Ubuntu Linux
  • SUSE Linux
  • Oracle Linux
  • SUSE openSUSE
  • Open Source Linux Kernel
  • Dell NetWorker

Productinfo

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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

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

Exploitinginfo

Class: Null pointer dereference
CWE: CWE-476 / CWE-404
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: 271973
Nessus Name: Linux Distros Unpatched Vulnerability : CVE-2025-40085

Threat Intelligenceinfo

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

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: Kernel 5.15.196/6.1.158/6.6.114/6.12.55/6.17.5/6.18-rc2
Patch: 736159f7b296d7a95f7208eb4799639b1f8b16a0/8d19a7ab28c7b9c207db5c5282afa8cc8595bcdb/576312eb436326b44b7010f4d9ae2b698df075ea/bba7208765d26e5e36b87f21dacc2780b064f41f/8503ac1a62075a085402e42a386b5c627c821a51/28412b489b088fb88dff488305fd4e56bd47f6e4

Timelineinfo

04/16/2025 CVE reserved
10/29/2025 +196 days Advisory disclosed
10/29/2025 +0 days VulDB entry created
02/12/2026 +106 days VulDB entry last update

Sourcesinfo

Vendor: kernel.org

Advisory: git.kernel.org
Status: Confirmed

CVE: CVE-2025-40085 (🔒)
GCVE (CVE): GCVE-0-2025-40085
GCVE (VulDB): GCVE-100-330402
CERT Bund: WID-SEC-2025-2441 - Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service

Entryinfo

Created: 10/29/2025 15:43
Updated: 02/12/2026 14:22
Changes: 10/29/2025 15:43 (59), 10/30/2025 00:11 (2), 12/21/2025 23:48 (7), 01/07/2026 05:59 (1), 02/12/2026 14:22 (1)
Complete: 🔍
Cache ID: 216::103

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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