CVE-2026-15158: Blocksy Companion <= 2.1.46 - Unauthenticated Arbitrary File Upload via 'blc-review-images[]' Parameter
The Blocksy Companion plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 2.1.46 via the saveattachments function. This is due to the Custom Fonts extension registering a wpcheckfiletypeandext 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 PATHINFOEXTENSION — 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.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
WordPress Blocksy Companion (blocksy-companion-pro)to a version that resolves this vulnerability.Fixed in 2.1.46 - Configuration
If using Blocksy Companion Pro, disable the Custom Fonts extension when the WooCommerce Extra (Advanced Reviews) extension is active to prevent the vulnerable wp_check_filetype_and_ext filter (vulnerability affects versions up to and including 2.1.46).
Blocksy Companion (blocksy-companion-pro) - Custom Fonts extension Custom Fonts extension active state = disable
Event History
Frequently Asked Questions
What is the severity of CVE-2026-15158?
CVE-2026-15158 has a critical severity rating of 9.8.
How does CVE-2026-15158 affect Blocksy Companion?
CVE-2026-15158 allows unauthorized users to upload arbitrary files due to a vulnerability in the save_attachments function.
What versions of Blocksy Companion are affected by CVE-2026-15158?
All versions of Blocksy Companion up to and including 2.1.46 are affected by CVE-2026-15158.
How do I fix CVE-2026-15158?
To mitigate CVE-2026-15158, update Blocksy Companion to a version beyond 2.1.46.
What type of vulnerability is identified in CVE-2026-15158?
CVE-2026-15158 is classified as a Malicious File Upload vulnerability.