Exposures › CVE-2026-15158
A WordPress plugin allows unauthenticated attackers to upload executable files via double-extension filenames, enabling remote code execution.
The Blocksy Companion plugin's Custom Fonts extension fails to validate file extensions strictly, permitting shell.woff2.php uploads that bypass MIME checks and enable RCE. DIB orgs using WordPress for sensitive systems face critical exposure; patching is mandatory to prevent unauthorized code execution.
Shame score — A critical RCE vulnerability in a WordPress plugin stems from a common double-extension bypass flaw rather than a novel attack vector or vendor negligence.
The Blocksy Companion plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.1.46 via the save_attachments function. This is due to the Custom Fonts extension registering a wp_check_filetype_and_ext filter that approves any filename containing .woff2 or .ttf as a substring via strpos() rather than validating that those strings appear as the final extension via PATHINFO_EXTENSION — allowing double-extension filenames such as shell.woff2.php to pass MIME validation and be handled as permitted font files. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. This vulnerability is only exploitable when the premium version of the plugin (blocksy-companion-pro) is installed with both the WooCommerce Extra (Advanced Reviews) and Custom Fonts extensions active; the free blocksy-companion plugin does not contain the vulnerable code paths.
No correlated FedRAMP products.