CVE-2026-43187 is a high-severity vulnerability in the Linux kernel's XFS filesystem related to the management of attribute leaf freemap entries. The flaw involves improper handling of zero-length freemap entries, which can lead to overlapping freemap entries and potential allocation of extended attributes over existing data, causing data loss. This bug has existed for a long time and was addressed by zeroing out the base of any freemap entry with zero size to prevent confusion and subsequent data corruption.