Blocksy Companion: Dangerous file upload
Blocksy Companion is affected by dangerous file upload. The vulnerable path is reachable without authentication. Successful exploitation can place attacker-controlled executable content on the server and may lead to full site compromise. The published affected range is <= 2.1.46.
- Component
- Blocksy Companion
- Plugin slug
blocksy-companion- Affected
- <= 2.1.46
- Safe version
> 2.1.46- Published
- Jul 09, 2026
This CVE was published Jul 09, 2026 and is one of 12 known issues for this plugin.
Update, patch or deactivate.
Update Blocksy Companion to a release after 2.1.46, or disable and remove it until a fixed version is available.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical 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.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H