kleor Contact Manager Plugin up to 9.1.2 on WordPress Extension Derivation Routine add_message unrestricted upload

Summaryinfo

A vulnerability was found in kleor Contact Manager Plugin up to 9.1.2. It has been rated as critical. Affected by this vulnerability is the function add_message of the component Extension Derivation Routine. This manipulation causes unrestricted upload. This vulnerability is registered as CVE-2026-109218. Remote exploitation of the attack is possible. No exploit is available.

Detailsinfo

A vulnerability classified as critical was found in kleor Contact Manager Plugin up to 9.1.2. Affected by this vulnerability is the function add_message of the component Extension Derivation Routine. 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 Contact Manager plugin for WordPress is vulnerable to Arbitrary File Upload in all versions up to, and including, 9.1.2 via the add_message function. This is due to an incomplete extension blacklist that fails to detect dangerous extensions when a trailing dot causes the extension-derivation routine to return an empty string, which sanitize_file_name() then silently removes before the file is written to disk. This makes it possible for unauthenticated attackers to upload files that may be executable, which makes remote code execution possible. Successful code execution additionally requires the server to use Apache with libapache2-mod-php (which maps .phar to PHP by default) and the attacker to retrieve the uploaded file within the brief window before it is removed by unlink() at end of request.

It is possible to read the advisory at wordfence.com. This vulnerability is known as CVE-2026-109218 since 10/12/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/28/2026). The attack technique deployed by this issue is T1608.002 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

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Productinfo

Type

• WordPress Plugin

Vendor

• kleor

Name

• Contact Manager Plugin

Version

• 9.1.0
• 9.1.1
• 9.1.2

CPE 2.3info

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CPE 2.2info

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