CVE-2026-87909: WP Photo Album Plus <= 9.2.09.002 - Authenticated (Subscriber+) Remote Code Execution via Multipart Upload Filename via ImageMagick Argument Injection

The WP Photo Album Plus plugin for WordPress is vulnerable to Remote Code Execution in all versions via the wppaimagemagick function. This is due to insufficient sanitization of the multipart upload filename before concatenation into an ImageMagick command string executed via exec(), with only escapeshellcmd() applied to the whole command rather than quoting individual arguments. This makes it possible for authenticated attackers, with subscriber-level access and above, to execute code on the server. escapeshellcmd() escapes shell metacharacters but does not prevent argument injection because spaces remain as argument separators, and the filename sanitization applied at the database layer is never applied to the physical temporary file path used for ImageMagick processing.