specialk Blackhole for Bad Bots Plugin up to 3.8 on WordPress sanitize_text_field cross site scripting

Summaryinfo

A vulnerability was found in specialk Blackhole for Bad Bots Plugin up to 3.8 on WordPress. It has been declared as problematic. This affects the function sanitize_text_field. Executing a manipulation can lead to cross site scripting. This vulnerability appears as CVE-2026-4329. The attack may be performed from remote. There is no available exploit. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as problematic was found in specialk Blackhole for Bad Bots Plugin up to 3.8 on WordPress. This vulnerability affects the function sanitize_text_field. The manipulation with an unknown input leads to a cross site scripting vulnerability. The CWE definition for the vulnerability is CWE-79. The product does not neutralize or incorrectly neutralizes user-controllable input before it is placed in output that is used as a web page that is served to other users. As an impact it is known to affect integrity. CVE summarizes:

The Blackhole for Bad Bots plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the User-Agent HTTP header in all versions up to and including 3.8. This is due to insufficient input sanitization and output escaping. The plugin uses sanitize_text_field() when capturing bot data (which strips HTML tags but does not escape HTML entities like double quotes), then stores the data via update_option(). When an administrator views the Bad Bots log page, the stored data is output directly into HTML input value attributes (lines 75-83) without esc_attr() and into HTML span content without esc_html(). This makes it possible for unauthenticated attackers to inject arbitrary web scripts that execute when an administrator views the Blackhole Bad Bots admin page.

The weakness was presented by Huynh Pham Thanh Luc. The advisory is shared for download at wordfence.com. This vulnerability was named CVE-2026-4329 since 03/17/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Successful exploitation requires user interaction by the victim. There are known technical details, but no exploit is available. The MITRE ATT&CK project declares the attack technique as T1059.007.

Upgrading to version 3.8 eliminates this vulnerability.

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Productinfo

Type

• WordPress Plugin

Vendor

• specialk

Name

• Blackhole for Bad Bots Plugin

Version

• 3.0
• 3.1
• 3.2
• 3.3
• 3.4
• 3.5
• 3.6
• 3.7
• 3.8

CPE 2.3info

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CPE 2.2info

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Once again VulDB remains the best source for vulnerability data.

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