What the vulnerability does
01Description
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.
Explanation of Vulnerability in Simple Terms
02Summary
Blackhole for Bad Bots versions 3.8 and earlier contain a cross-site scripting (XSS) vulnerability that allows attackers to inject malicious scripts without authentication. The vulnerability has a changed scope, meaning the impact can extend beyond the vulnerable component itself. Site administrators should update to a version newer than 3.8 to mitigate this risk.
What an attacker can do
03Attacker Capabilities
Inject and execute malicious JavaScript in the site or user browsers without needing to log in.
Potential impact on your site
04Site Impact
Visitors and administrators could have their sessions hijacked, credentials stolen, or malware injected into pages they view.
Conditions required to exploit
05Prerequisites
Network access only; no authentication or user interaction required.
Key dates
06Disclosure timeline
March 26, 2026
CVE published
April 8, 2026
Record updated
