CVE-2025-22126 is a use-after-free (UAF) vulnerability in the Linux kernel's md (multiple device) subsystem. It occurs during iteration over the all_mddevs list in md_notify_reboot() and md_exit() functions, where a race condition can lead to dereferencing freed memory. The vulnerability has a high severity with a CVSS score of 7.8, impacting confidentiality, integrity, and availability. The issue arises from improper locking and reference counting during list iteration, which can cause unsafe memory access. The fix involves changing the iteration method and introducing a helper function to safely manage references and prevent premature freeing of mddev structures.