creativethemeshq Blocksy Companion Plugin up to 2.1.46 Custom Fonts Extension shell.woff2.php save_attachments unrestricted upload

Summaryinfo

A vulnerability was found in creativethemeshq Blocksy Companion Plugin up to 2.1.46 and classified as critical. The impacted element is the function save_attachments of the file shell.woff2.php of the component Custom Fonts Extension. Executing a manipulation can lead to unrestricted upload. The identification of this vulnerability is CVE-2026-15158. The attack may be launched remotely. There is no exploit available.

Detailsinfo

A vulnerability classified as critical was found in creativethemeshq Blocksy Companion Plugin up to 2.1.46. This vulnerability affects the function save_attachments of the file shell.woff2.php of the component Custom Fonts Extension. The manipulation with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at wordfence.com. This vulnerability was named CVE-2026-15158 since 07/08/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 07/09/2026). The MITRE ATT&CK project declares the attack technique as T1608.002.

By approaching the search of inurl:shell.woff2.php it is possible to find vulnerable targets with Google Hacking.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• creativethemeshq

Name

• Blocksy Companion Plugin

Version

• 2.1.0
• 2.1.1
• 2.1.2
• 2.1.3
• 2.1.4
• 2.1.5
• 2.1.6
• 2.1.7
• 2.1.8
• 2.1.9
• 2.1.10
• 2.1.11
• 2.1.12
• 2.1.13
• 2.1.14
• 2.1.15
• 2.1.16
• 2.1.17
• 2.1.18
• 2.1.19
• 2.1.20
• 2.1.21
• 2.1.22
• 2.1.23
• 2.1.24
• 2.1.25
• 2.1.26
• 2.1.27
• 2.1.28
• 2.1.29
• 2.1.30
• 2.1.31
• 2.1.32
• 2.1.33
• 2.1.34
• 2.1.35
• 2.1.36
• 2.1.37
• 2.1.38
• 2.1.39
• 2.1.40
• 2.1.41
• 2.1.42
• 2.1.43
• 2.1.44
• 2.1.45
• 2.1.46

CPE 2.3info

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Once again VulDB remains the best source for vulnerability data.

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