CVE-2026-1490
📋 TL;DR
This vulnerability allows unauthenticated attackers to bypass authorization and install arbitrary WordPress plugins via reverse DNS spoofing. It affects WordPress sites using the CleanTalk Spam Protection plugin with invalid API keys. Successful exploitation can lead to remote code execution if vulnerable plugins are installed.
💻 Affected Systems
- CleanTalk Spam Protection, Anti-Spam, FireWall by CleanTalk WordPress plugin
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Attackers achieve remote code execution, gain full control of the WordPress site, and potentially compromise the entire server infrastructure.
Likely Case
Attackers install malicious plugins that create backdoors, steal data, or use the site for further attacks like phishing or malware distribution.
If Mitigated
With valid API keys, the vulnerability cannot be exploited, providing complete protection.
🎯 Exploit Status
Exploitation requires reverse DNS spoofing capability and an invalid API key. The vulnerability is well-documented with public references.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.72 and later
Vendor Advisory: https://plugins.trac.wordpress.org/changeset/3454488/cleantalk-spam-protect
Restart Required: No
Instructions:
1. Log into WordPress admin panel. 2. Navigate to Plugins → Installed Plugins. 3. Find CleanTalk Spam Protection plugin. 4. Click 'Update Now' if available. 5. Alternatively, download version 6.72+ from WordPress repository and manually update.
🔧 Temporary Workarounds
Ensure Valid API Key
allConfigure a valid API key for the CleanTalk plugin to prevent exploitation
Disable Plugin
linuxTemporarily disable the CleanTalk plugin until patched
wp plugin deactivate cleantalk-spam-protect
🧯 If You Can't Patch
- Ensure CleanTalk API key is valid and properly configured
- Implement network controls to prevent reverse DNS spoofing attacks
🔍 How to Verify
Check if Vulnerable:
Check WordPress admin panel → Plugins → Installed Plugins for CleanTalk version. If version ≤6.71 and API key is invalid, system is vulnerable.Check Version:
wp plugin get cleantalk-spam-protect --field=versionVerify Fix Applied:
Confirm CleanTalk plugin version is 6.72 or higher in WordPress admin panel.📡 Detection & Monitoring
Log Indicators:
- Unauthorized plugin installation attempts in WordPress logs
- Remote calls to checkWithoutToken function with suspicious parameters
Network Indicators:
- Unusual reverse DNS lookups from WordPress server
- Unexpected plugin installation traffic
SIEM Query:
source="wordpress" AND (event="plugin_installed" OR event="plugin_activated") AND user="unauthenticated"🔗 References
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/ApbctWP/RemoteCalls.php#L69
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/Common/Helper.php#L64
- https://plugins.trac.wordpress.org/changeset/3454488/cleantalk-spam-protect#file473
- https://www.wordfence.com/threat-intel/vulnerabilities/id/cb603be6-4a12-49e1-b8cc-b2062eb97f16?source=cve
