CVE-2026-6261: Betheme <= 28.4 - Authenticated (Author+) Arbitrary File Upload to Remote Code Execution via Icon Pack Upload

The Betheme theme for WordPress is vulnerable to Arbitrary File Upload in versions up to, and including, 28.4. This is due to the upload_icons() function workflow moving and unzipping user-controlled ZIP files into a public uploads directory without validating extracted file types. This makes it possible for authenticated attackers, with author-level access and above, to upload arbitrary files (including PHP) and achieve remote code execution via the Icons icon-pack upload flow.