CVE-2026-84374: Laravel Excel writes exports outside the configured filesystem disk when given a caller-controlled path

Excel::store() resolved the destination path against the process working directory rather than the configured filesystem disk. When that path resolved to an existing file, the export was written straight to it with fopen(), bypassing the disk entirely. An application that passes a user-controlled value as the export path could therefore be made to overwrite an arbitrary existing file that the PHP process can write to, with content the user controls.