CVE-2026-13430: Unrestricted Upload of File with Dangerous Type

The Post Export Import with Media plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 1.13.1 via the import_media_file_secure function. This is due to insufficient file extension validation caused by a trailing-dot filename bypass, where the extension allow-list check in ajax_import_media_start() uses pathinfo() on the raw ZIP entry name (e.g., 'shell.php.'), which returns an empty string for the extension, causing the allow-list guard to be skipped and the file to be extracted to a temporary location, after which import_media_file_secure() copies it into the WordPress uploads directory without re-validating the extension. This makes it possible for authenticated attackers, with administrator-level access and above, to upload files that may be executable, which makes remote code execution possible.