niteo CMP Plugin up to 4.1.16 on WordPress ZIP File cmp-premium-themes unrestricted upload

Summaryinfo

A vulnerability classified as critical has been found in niteo CMP Plugin up to 4.1.16 on WordPress. This impacts an unknown function of the file wp-content/plugins/cmp-premium-themes/ of the component ZIP File Handler. This manipulation causes unrestricted upload. This vulnerability is tracked as CVE-2026-6518. The attack is possible to be carried out remotely. No exploit exists. It is recommended to upgrade the affected component.

Detailsinfo

A vulnerability classified as critical was found in niteo CMP Plugin up to 4.1.16 on WordPress. Affected by this vulnerability is some unknown processing of the file wp-content/plugins/cmp-premium-themes/ of the component ZIP File Handler. The manipulation with an unknown input leads to a unrestricted upload vulnerability. The CWE definition for the vulnerability is CWE-434. The product allows the attacker to upload or transfer files of dangerous types that can be automatically processed within the product's environment. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

The weakness was disclosed by ll. It is possible to read the advisory at wordfence.com. This vulnerability is known as CVE-2026-6518 since 04/17/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The attack technique deployed by this issue is T1608.002 according to MITRE ATT&CK.

Upgrading to version 4.1.16 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-23654). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• niteo

Name

• CMP Plugin

Version

• 4.1.0
• 4.1.1
• 4.1.2
• 4.1.3
• 4.1.4
• 4.1.5
• 4.1.6
• 4.1.7
• 4.1.8
• 4.1.9
• 4.1.10
• 4.1.11
• 4.1.12
• 4.1.13
• 4.1.14
• 4.1.15
• 4.1.16

CPE 2.3info

• 🔒
• 🔒
• 🔒

CPE 2.2info

• 🔒
• 🔒
• 🔒

CVSSv4info

CVSSv3info

CVSSv2info

Exploitinginfo

Threat Intelligenceinfo

Countermeasuresinfo

Timelineinfo

Sourcesinfo

Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Discussion