# CVE-2026-103424: CleanTalk Anti-Spam plugin for WordPress stored XSS

Source: https://junglewise.ai/threats/cve-2026-103424-the-anti-spam-by-cleantalk-spam-protection-without-captcha  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-10. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-103424 · Severity: medium · CVSS 5.4 · Published 2026-10-10

The CleanTalk Anti-Spam plugin protects WordPress sites from spam comments and bot attacks. A vulnerability allows unauthenticated attackers to inject malicious scripts through comments that execute for all site visitors once the attacker's initial comment is approved. On most WordPress sites, subsequent comments from the same email address auto-approve, enabling immediate exploitation.

Vendors: [CleanTalk](https://junglewise.ai/threats/vendors/cleantalk).

## Quick answers

**Is CVE-2026-103424 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-103424 being exploited in the wild.

**How severe is CVE-2026-103424?** Medium severity, with a CVSS score of 5.4, published 10 October 2026.

**Which products and versions are affected?** CleanTalk Anti-Spam – Spam Protection Without CAPTCHA up to 6.88.

**Is there a fix for CVE-2026-103424?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-103424 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-103424?** Check whether you run CleanTalk Anti-Spam – Spam Protection Without CAPTCHA at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

The plugin fails to properly sanitize and escape user input in the comment parameter, allowing stored XSS injection. An unauthenticated attacker can inject arbitrary JavaScript that persists in the database and executes in the browsers of all users who view the affected page. The vulnerability is practical because WordPress's default moderation policy auto-approves subsequent comments from previously-approved email addresses.

## Affected products

- CleanTalk Anti-Spam – Spam Protection Without CAPTCHA up to 6.88

## Timeline

- 2026-10-10: disclosed

## References

- [https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/cleantalk.php](https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/cleantalk.php)
- [https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/ApbctWP/ContactsEncoder/ContactsEncoder.php](https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.88/lib/Cleantalk/ApbctWP/ContactsEncoder/ContactsEncoder.php)

## Related threats

- [CleanTalk Anti-Spam stored cross-site scripting in user email](https://junglewise.ai/threats/cve-2026-109198-the-anti-spam-by-cleantalk-spam-protection-without-captcha)