CVE-2026-6518

Description

The CMP – Coming Soon & Maintenance Plugin by NiteoThemes plugin for WordPress is vulnerable to arbitrary file upload and remote code execution in all versions up to, and including, 4.1.16 via the `cmp_theme_update_install` AJAX action. This is due to the function only checking for the `publish_pages` capability (available to Editors and above) instead of `manage_options` (Administrators only), combined with a lack of proper validation on the user-supplied file URL and no verification of the downloaded file's content before extraction. This makes it possible for authenticated attackers, with Administrator-level access and above, to force the server to download and extract a malicious ZIP file from a remote attacker-controlled URL into a web-accessible directory (`wp-content/plugins/cmp-premium-themes/`), resulting in remote code execution. Due to the lack of a nonce for Editors, they are unable to exploit this vulnerability.

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CVSS v3.1 Score

8.8

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0007

Probability of exploitation

0.21%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-434 Unrestricted Upload

References

Other References

https://plugins.trac.wordpress.org/browser/cmp-coming-soon-maintenance/tags/4.1.16/niteo-cmp.php#L1421 https://plugins.trac.wordpress.org/browser/cmp-coming-soon-maintenance/tags/4.1.16/niteo-cmp.php#L1437 https://plugins.trac.wordpress.org/browser/cmp-coming-soon-maintenance/tags/4.1.16/niteo-cmp.php#L1447 https://plugins.trac.wordpress.org/changeset?old_path=%2Fcmp-coming-soon-maintenance/tags/4.1.16&new_path=%2Fcmp-coming-soon-maintenance/tags/4.1.17 https://www.wordfence.com/threat-intel/vulnerabilities/id/d6fb275b-dbba-46df-b170-977ef4a84c4c?source=cve

Frequently Asked Questions

What is CVE-2026-6518? +

The CMP – Coming Soon & Maintenance Plugin by NiteoThemes plugin for WordPress is vulnerable to arbitrary file upload and remote code execution in all versions up to, and including, 4.1.16 via the `cmp_theme_update_install` AJAX action. This is due to the function only checking for the `publish_pages` capability (available to Editors and above) instead of `manage_options` (Administrators only), combined with a lack of proper validation on the user-supplied file URL and no verification of the downloaded file's content before extraction. This makes it possible for authenticated attackers, with Administrator-level access and above, to force the server to download and extract a malicious ZIP file from a remote attacker-controlled URL into a web-accessible directory (`wp-content/plugins/cmp-premium-themes/`), resulting in remote code execution. Due to the lack of a nonce for Editors, they are unable to exploit this vulnerability. It has a CVSS v3.1 base score of 8.8 (HIGH).

How severe is CVE-2026-6518? +

CVE-2026-6518 has a CVSS v3.1 score of 8.8 out of 10, rated HIGH. This is a high-severity vulnerability that should be prioritized for patching. The EPSS score is 0.0007, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-6518? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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