This vulnerability in Campaign Monitor for WordPress (up to version 2.9.1) is due to missing authorization checks in the forms-for-campaign-monitor component, allowing attackers with some privileges to bypass intended access controls. The CVSS 3.1 base score is 4.3 (medium), reflecting a network attack vector with low complexity and no user interaction required, but limited impact confined to integrity. The issue is publicly disclosed but lacks an official patch or vendor advisory detailing remediation steps.

The vulnerability allows an attacker with limited privileges to perform unauthorized actions that could alter data or configurations within the affected plugin, impacting integrity. There is no impact on confidentiality or availability. No known exploitation in the wild has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until an official fix is released, restrict access to the plugin's administrative functions to trusted users only and monitor for unusual activity related to Campaign Monitor forms. Avoid granting unnecessary privileges to users who can interact with the plugin.