CVE-2026-15158
CriticalCVSS 9.8Exploitation Probability (EPSS)
Elevated risk58th percentile - higher than 58% of all known CVEs
Summary
The Blocksy Companion plugin for WordPress is vulnerable to arbitrary file upload in versions up to 2.1.46. The flaw lies in the save_attachments function, which improperly validates file extensions, allowing double-extension files like shell.woff2.php to bypass MIME checks. This can lead to remote code execution, but exploitation requires the premium plugin with specific extensions active.
Risk Assessment
An unauthenticated attacker could upload a malicious file and achieve remote code execution, compromising the server's confidentiality, integrity, and availability.
Recommendation
Update Blocksy Companion to version 2.1.47 or later immediately. If using the premium version, ensure WooCommerce Extra and Custom Fonts extensions are updated or temporarily disable them.
Original NVD description (English source)
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.