CVE-2025-38223 is a vulnerability in the Linux kernel's Ceph filesystem component that causes a kernel BUG when handling encrypted inodes with unaligned file sizes. This issue triggers a kernel crash (BUG_ON) during certain file operations, leading to denial of service. The flaw was identified in kernel version 6.13.0-rc5+ and is related to the ceph messenger code. The vulnerability does not impact confidentiality or integrity but causes system instability.