CVE-2026-15158: creativethemeshq blocksy companion

Vulnerability summary

CVE-2026-15158 is a critical (CVSS 9.8) vulnerability in creativethemeshq blocksy companion. EPSS estimates a 1.07% chance of exploitation in the next 30 days, higher than 64.2% of scored vulnerabilities. Fixed in 2.1.47.

Timeline

1. 09-07-2026
   PublishedVulnerability first disclosed.
2. 09-07-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-434Unrestricted Upload of File with Dangerous TypeThe product allows the upload or transfer of dangerous file types that are automatically processed within its environment.