Vulnerabilities / Anti-Spam by CleanTalk / WPSEC-2026-2021
Anti-Spam by CleanTalk <= 6.90 - Unauthenticated Open Redirect via SpamFireWall Block Page
Medium 6.1
CWE-601Fixed in 6.91
- ID
- WPSEC-2026-2021
- Plugin
- Anti-Spam, Spam FireWall by CleanTalk (cleantalk-spam-protect)
- Affected
- all versions before 6.91
- Remediation
- Update to 6.91 or later.
- CVSS 3.1
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- Weakness
- CWE-601
- Usage
- Plugin High · Affected versions High among sites WPSec scans, 2026-10-30
- Attack surface
- Anti-Spam by CleanTalk on WPSec AttackSurface
- Fix released
- Published
Description
The Anti-Spam, Spam FireWall by CleanTalk plugin for WordPress is vulnerable to Open Redirect via the request URI shown on the SpamFireWall block page in all versions up to, and including, 6.90, due to the {REQUEST_URI} link target being escaped only with esc_url(), which keeps protocol-relative values such as '//example.com'. The block page can be shown to any visitor with the 'sfw_test_ip' parameter. This makes it possible for unauthenticated attackers to send users to an external site when they click the 'click to pass' link on a crafted URL.
References
- https://wpsec.com/vuln/WPSEC-2026-2021/
- https://plugins.svn.wordpress.org/cleantalk-spam-protect/tags/6.91/
- https://wordpress.org/plugins/cleantalk-spam-protect/
Published by WPSec. Provided as is, without warranty. Corrections: contact us.
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