Security readout for executives and security teams
Plain-English summary
A critical CleanTalk WordPress anti-spam plugin flaw can let unauthenticated attackers install and activate arbitrary plugins, but only when the site has an invalid CleanTalk API key. This could become full site compromise if the attacker activates another vulnerable plugin. No cited source says this is actively exploited.
Executive priority
Treat this as urgent for WordPress environments using CleanTalk, especially where API key status is unmanaged. Prioritize version validation, API key verification, and plugin audit. Business risk is site takeover through malicious or vulnerable plugin activation.
Technical view
CVE-2026-1490 is an authorization bypass in CleanTalk Spam protection/Honeypot/Anti-Spam up to and including 6.71. The issue involves reverse DNS PTR spoofing in checkWithoutToken, mapped to CWE-350. Network attackers need no credentials or user interaction. Impact is arbitrary plugin installation/activation, with potential RCE through a subsequently vulnerable plugin.
Likely exposure
WordPress sites running CleanTalk Spam protection, Honeypot, Anti-Spam by CleanTalk version 6.71 or earlier are potentially exposed if their CleanTalk API key is invalid. Sites with a valid API key are specifically described as not meeting the noted exploit condition.
Exploitation context
The CVSS is 9.8 because exploitation is remote, unauthenticated, low complexity, and can affect confidentiality, integrity, and availability. The public sources do not report active exploitation, and CISA KEV status is false in the provided data.
Researcher notes
Key constraints matter: sources state exploitation requires an invalid API key, and RCE depends on another vulnerable plugin being installed and activated. The issue centers on trust in reverse DNS/PTR validation in a remote-call path. Do not assume broad exploitability without confirming the API key condition.
Mitigation direction
- Update the CleanTalk plugin to a version newer than 6.71 if available.
- Verify the CleanTalk API key is valid on every WordPress site.
- Review vendor and Wordfence guidance for the confirmed fixed version.
- Remove unneeded WordPress plugins to reduce post-bypass impact.
- Audit newly installed or activated plugins for unauthorized changes.
Validation and detection
- Inventory WordPress sites using the CleanTalk anti-spam plugin.
- Confirm installed CleanTalk plugin versions are newer than 6.71.
- Check whether each site’s CleanTalk API key is valid.
- Review WordPress plugin installation and activation history.
- Monitor for unexpected plugin additions or configuration changes.
Public sources used
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Conservative CVE-to-ATT&CK context
These mappings and lookup hints may be relevant to the vulnerability behavior, CWE, affected product, or exposure path. Glexia-inferred context is not an official MITRE, ATT&CK, CWE, or CVE Program mapping.
ATT&CK lookup starting points
Use these exact CWE pages and searches to review the Glexia ATT&CK library from this CVE's weakness and description context.
CWE-350: Exact CWE lookup
Use the exact CWE identifier as the starting point before reviewing related ATT&CK behavior. Open the exact CWE lookup page first, then review the ATT&CK searches from that MITRE weakness context. This is a Glexia lookup hint, not an official ATT&CK mapping.
Open ATT&CK lookupExecution behavior lookup
The CVE wording references code or command execution, so execution technique review may help defensive triage. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupPrivilege behavior lookup
The CVE wording references privilege impact, so privilege escalation and authorization behavior review may help. This is a Glexia inferred lookup path, not an official MITRE, ATT&CK, or CVE Program mapping.
Open ATT&CK lookupCVE-2026-1490 mapping review
Open the CVE-to-ATT&CK bridge for reviewed, inferred, or future official mappings tied to this CVE.
Open ATT&CK lookup- Severity
- Critical
- CVSS
- 9.8 (3.1)
- Known Exploited
- No
- Published
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
CNA and ADP enrichment extracted from CVE v5
These fields come from the CVE record and ADP containers, not from Glexia's Take. They preserve time-varying source decisions such as CISA SSVC, KEV status, CVSS metrics, and provider references.
CVSS vector scores
1 official scoreWe collect every scored CVSS vector available in the official CNA and ADP containers. When more than one version is present, the table keeps the source vectors side by side instead of collapsing them into the highest score.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H3.95.9Primary CVE scoreVulnerability scoring details
Base CVSS 3.1 score
9.8CriticalVector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Source materials
- CVE List V5 sourceCVE List V5
- https://www.wordfence.com/threat-intel/vulnerabilities/id/cb603be6-4a12-49e1-b8cc-b2062eb97f16?source=cveCVE reference
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/ApbctWP/RemoteCalls.php#L69CVE reference
- https://plugins.trac.wordpress.org/browser/cleantalk-spam-protect/trunk/lib/Cleantalk/Common/Helper.php#L64CVE reference
- https://plugins.trac.wordpress.org/changeset/3454488/cleantalk-spam-protect#file473CVE reference
Products and packages named in the record
CWE details
CWE links open Glexia weakness intelligence pages with official CWE context, developer remediation guidance, and related CVE mappings.
Reliance on Reverse DNS Resolution for a Security-Critical Action
Reliance on Reverse DNS Resolution for a Security-Critical Action represents a recurring weakness pattern that can create exploitable paths when design, validation, or implementation controls are missing.