CVE-2025-40197: 
Linux Kernel vulnerability analysis and mitigation

CVE-2025-40197 was disclosed on November 12, 2025, affecting the Linux kernel. The vulnerability relates to an issue where the device minor number is incorrectly handled in the media subsystem's media controller (mc) component, specifically where the device minor should not be cleared after the device is released (NVD, Ubuntu).

The vulnerability exists in the media controller (mc) component of the Linux kernel, specifically involving improper handling of device minor numbers. The issue occurs when the device minor number is cleared at an incorrect time during the device release process (NVD).

The vulnerability affects various Linux distributions and their kernel versions. According to the Debian security tracker, the vulnerability has been fixed in newer versions while remaining vulnerable in some older releases (Debian Tracker).

The vulnerability has been patched in multiple Linux distributions. Ubuntu has marked this with medium priority and has implemented fixes across various kernel versions. Many Ubuntu kernel flavors including linux-aws, linux-azure, and linux-gcp are marked as 'Not affected' or have been patched (Ubuntu).