Kit (formerly ConvertKit) – Email Subscribers, Email Newsletter, Email Marketing, Landing Pages and Membership <= 3.5.0 - Unauthenticated Sensitive Information Exposure via AJAX Requests

ID

WPSEC-2026-2851

Plugin

Kit (formerly ConvertKit) – Email Subscribers, Email Newsletter, Email Marketing, Landing Pages and Membership (convertkit)

Affected

from 2.1.0 before 3.5.1

Remediation

Update to 3.5.1 or later.

CVSS 3.1

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

Weakness

CWE-200

Usage

Plugin Medium · Affected versions Medium among sites WPSec scans, 2026-11-12

Attack surface

Kit (formerly ConvertKit) – Email Subscribers, Email Newsletter, Email Marketing, Landing Pages and Membership on WPSec AttackSurface

Fix released

2026-11-10

Published

2026-11-12

Description

The Kit (formerly ConvertKit) plugin for WordPress is vulnerable to Sensitive Information Exposure in all versions up to, and including, 3.5.0. This is due to the Member Content filter not restricting post content that is output during AJAX requests, because the filter is only registered on the 'wp' action, which does not run for AJAX requests. This makes it possible for unauthenticated attackers to read member-only content of restricted pages and posts when a theme or plugin outputs post content over AJAX, for example through a 'load more' button.

References

• https://wpsec.com/vuln/WPSEC-2026-2851/
• https://plugins.svn.wordpress.org/convertkit/tags/3.5.1/
• https://wordpress.org/plugins/convertkit/

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