🔐 CVE Alert

CVE-2026-103424

MEDIUM 5.4

Anti-Spam by CleanTalk <= 6.88 - Unauthenticated Stored Cross-Site Scripting via Comment Content via ContactsEncoder Greedy Regex

CVSS Score
5.4
EPSS Score
0.0%
EPSS Percentile
0th

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.

CWE CWE-79
Vendor cleantalk
Product anti-spam by cleantalk – spam protection without captcha
Published Oct 10, 2026
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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability

Affected Versions

cleantalk / Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA
0 ≤ 6.88

References

NVD ↗ CVE.org ↗ EPSS Data ↗
wordfence.com: https://www.wordfence.com/threat-intel/vulnerabilities/id/c3a80bcd-170b-469b-b090-8f806f87b8d7?source=cve plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L831 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L841 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/Common/ContactsEncoder/ContactsEncoder.php#L273 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/ApbctWP/ContactsEncoder/ContactsEncoder.php#L97 plugins.trac.wordpress.org: https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/cleantalk.php#L248

Credits

Maciej Komorowski