by Kastro
Paper/Archive/CVE-2026-1490

CVE-2026-1490

cleantalk Spam protection, Honeypot, Anti-Spam by CleanTalk — Spam protection, Honeypot, Anti-Spam by CleanTalk <= 6.71 - Authorization Bypass via Reverse DNS (PTR record) Spoofing to Unauthenticated Arbitrary Plugin Installation

EPSS 1%CVSS 9.8
critical.is priorityof 100
43
CVSS 9.8 (CNA)9.8 / 10 × 3029.4Not in CISA KEV+300.0EPSS percentile 70.0.700 × 2014.0No public exploit+100.0SSVC exploitation: none+100.0
Description · from the CVE record

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.

Affected

ProductAffectedFixed inSource
Spam protection, Honeypot, Anti-Spam by CleanTalk≤ 6.71–CNA

Scores by source

Wordfence (CNA)9.8CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: yes · Technical impact: total

References

refwordfence.com/threat-intel/vulnerabilities/id/cb603be6-4a12-49e1-b8cc-b2062eb97f16?source=cverefplugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/ApbctWP/RemoteCalls.php#L69refplugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/Common/Helper.php#L64refplugins.trac.wordpress.org/changeset/3454488/cleantalk-spam-protect#file473