CyberSecBulletin
CVE-2026-1490NVD status: Deferred

Spam protection, Honeypot, Anti-Spam by…: Reliance on Reverse DNS Resolution for a Security-Critical Action

Published Updated By the CyberSecBulletin desk

CVE-2026-1490 is a critical-severity reliance on reverse DNS resolution for a security-critical action vulnerability in Spam protection, Honeypot, Anti-Spam by CleanTalk from CleanTalk, with a CVSS 3.1 base score of 9.8 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected Spam protection, Honeypot, Anti-Spam by CleanTalk versions: 6.71 and earlier. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 1.26% chance of exploitation within 30 days, higher than 70% of scored CVEs.

Patch this week

Critical severity: a successful attack would have severe impact.

What to do

  1. Check which version of Spam protection, Honeypot, Anti-Spam by CleanTalk you run against the affected versions below, and install the vendor's latest release.
  2. Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.

Affected products and versions

VendorProductAffected versionsFixed in
CleantalkSpam protection, Honeypot, Anti-Spam by CleanTalk6.71 and earlierNot stated

Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.

How the severity score breaks down

Attack vector
NetworkCan be exploited remotely over a network, including the internet.
Attack complexity
LowNo special conditions are needed; the attack works reliably.
Privileges required
NoneNo account or login is needed.
User interaction
NoneNo action by a victim is required.
Scope
UnchangedImpact stays within the vulnerable component.
Confidentiality
HighAll data handled by the component can be read.
Integrity
HighData or code can be modified at will.
Availability
HighThe component can be taken down completely.

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (wordfence.com).

Official 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.

Source: the CVE record as published by its numbering authority, via NVD and CVE.org.

The underlying weakness: Reliance on Reverse DNS Resolution for a Security-Critical Action

The product performs reverse DNS resolution on an IP address to obtain the hostname and make a security decision, but it does not properly ensure that the IP address is truly associated with the hostname.

How developers prevent this class of flaw

  • Use other means of identity verification that cannot be simply spoofed. Possibilities include a username/password or certificate.
  • Perform proper forward and reverse DNS lookups to detect DNS spoofing.

More Reliance on Reverse DNS Resolution for a Security-Critical Action vulnerabilities (CWE-350)

Timeline

  1. CVE record published.
  2. CISA published its SSVC assessment (exploitation: none, automatable: yes, technical impact: total).
  3. Record last changed materially (score, affected products, status or references).

References

Other vulnerabilities in Spam protection, Honeypot, Anti-Spam by CleanTalk

All Spam protection, Honeypot, Anti-Spam by CleanTalk vulnerabilities

Recent Reliance on Reverse DNS Resolution for a Security-Critical Action vulnerabilities

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