Block for Mailchimp – Add Email Subscription Forms and Collect Leads vulnerability

The Block For Mailchimp – Easy Mailchimp Form Integration plugin for WordPress is vulnerable to Blind Server-Side Request Forgery in all versions up to, and including, 1.1.12 via the mcbSubmit_Form_Data(). This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.

Published 1 Oct 2025Updated 9 Oct 20264 sources
CVSS 4.0

What happened

The Block For Mailchimp – Easy Mailchimp Form Integration plugin for WordPress is vulnerable to Blind Server-Side Request Forgery in all versions up to, and including, 1.1.12 via the mcbSubmit_Form_Data(). This makes it possible for unauthenticated attackers to make web requests to arbitrary locations originating from the web application and can be used to query and modify information from internal services.

Affected versions

Block for Mailchimp – Add Email Subscription Forms and Collect Leads: 0 through 1.1.12 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.