CVE-2026-15158 CRITICAL

CVE-2026-15158: Blocksy Companion <= 2.1.46 - Unauthenticated Arbitrary File Upload via 'blc-review-images[]' Parameter

Vendor Creativethemeshq
Product Blocksy Companion
Weakness CWE-434 · Unrestricted file upload
Published July 9, 2026
Last update July 9, 2026
View on NVD All CVEs

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

What the vulnerability does

01Description

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.

Explanation of Vulnerability in Simple Terms

02Summary

Blocksy Companion versions up to 2.1.46 allow unauthenticated attackers to upload files without restriction. An attacker can upload malicious files directly to the site over the network, potentially gaining full control. No user interaction or special privileges are required. Sites running affected versions should update immediately.

What an attacker can do

03Attacker Capabilities

Upload malicious files to the site and run their own code on it.

Potential impact on your site

04Site Impact

Complete compromise of the site; attacker can read, modify, or delete all data and user accounts.

Conditions required to exploit

05Prerequisites

Network access only; no authentication or user interaction required.

Key dates

06Disclosure timeline

July 9, 2026 CVE published

Related vulnerabilities

08Related CVE

CVE-2026-58480 Blocksy Companion Pro < 2.1.47 Unauthenticated File Upload via save_attachments CVE-2026-39527 WordPress WpStream plugin < 4.11.2 - Arbitrary File Upload vulnerability CVE-2026-14894 Super Forms <= 6.3.313 - Unauthenticated Arbitrary File Upload via 'data' Parameter (datauristring / value) CVE-2026-4885 Piotnet Addons for Elementor Pro <= 7.1.70 - Unauthenticated Arbitrary File Upload via Form File Upload CVE-2026-40750 WordPress Kids Online Store theme <= 0.8.9 - Arbitrary File Upload vulnerability