CVE-2026-103424
MediumCVSS 5.4Summary
The Anti-Spam by CleanTalk plugin for WordPress up to version 6.88 is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter due to insufficient input sanitization and output escaping. Unauthenticated attackers can inject arbitrary web scripts that execute when a user accesses an injected page. The vulnerability is exploitable once a comment from the attacker's email is approved; on default WordPress installations, only the first comment from a given email is moderated, and subsequent comments auto-approve.
Risk Assessment
The organization is at risk of malicious script injection that could steal user data, hijack sessions, or spread malware on the site.
Recommendation
Update the Anti-Spam by CleanTalk plugin to the latest version with a fix. Also consider strengthening comment moderation policies and implementing mechanisms to detect and block malicious scripts.
Other vulnerabilities in Anti-Spam by CleanTalk
See all- CVE-2026-10770Medium
The Anti-Spam by CleanTalk plugin for Drupal contains a reflected Cross-site Scripting (XSS) vulnerability due to improper input neutralization during page generation. This affects versions from 0.0.0 to 9.7.1.
- CVE-2026-8071High
Vulnerability in the Anti-Spam by CleanTalk WordPress plugin before version 6.79: improper content sanitization in a custom shortcode used in email encoding. Unauthenticated attackers can inject arbitrary web scripts into approved comments.
Original NVD description (English source)
The Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'comment' parameter in all versions up to, and including, 6.88 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This vulnerability is exploitable once a comment from the attacker's email address has been approved; on default WordPress installations, only the first comment from a given email address is held for moderation, meaning subsequent comments auto-approve and immediately expose the payload to site visitors.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS