CVE detail
CVE-2026-1781
The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 4.11.1. This is due to the plugin trusting the `_mc4wp_action` POST parameter without validation, allowing unauthenticated attackers to force the form to process unsubscribe actions instead of subscribe actions. This makes it possible for unauthenticated attackers to arbitrarily unsubscribe any email address from the connected Mailchimp audience via the `_mc4wp_action` parameter, granted they can obtain the form ID (which is publicly exposed in the HTML source).
Buzz score
Why this CVE is surfacing
This all-time snapshot uses the same composite formula as Trending across a 30-year evidence window, rather than a current rolling window.
Buzz score components · mention 20.8 · diversity 20.0 · KEV 0.0 · OTX 0.0 · PoC 0.0
Why it matters now
Mention timeline
- Total mentions
- 0
- within the 30d window
- Peak daily
- 0
- highest bucket
Evidence
Source links by recency
7 source links · newest first
- https://www.wordfence.com/threat-intel/vulnerabilities/id/10262aa9-5656-4a2b-aeb5-060018798369?source=cvewww.wordfence.com
No excerpt available.
Third Party Advisorywww.wordfence.comMar 11, 2026, 2:16 AM - https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3477825%40mailchimp-for-wp%2Ftrunk&old=3443118%40mailchimp-for-wp%2Ftrunk&sfp_email=&sfph_mail=plugins.trac.wordpress.org
No excerpt available.
Patchplugins.trac.wordpress.orgMar 11, 2026, 2:16 AM - https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/class-form.php#L461plugins.trac.wordpress.org
No excerpt available.
Patchplugins.trac.wordpress.orgMar 11, 2026, 2:16 AM - https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/class-form-listener.php#L53plugins.trac.wordpress.org
No excerpt available.
Patchplugins.trac.wordpress.orgMar 11, 2026, 2:16 AM - https://plugins.trac.wordpress.org/browser/mailchimp-for-wp/tags/4.11.1/includes/forms/class-form-listener.php#L207plugins.trac.wordpress.org
No excerpt available.
Patchplugins.trac.wordpress.orgMar 11, 2026, 2:16 AM - https://github.com/ibericode/mailchimp-for-wordpress/commit/5fdebc2a5e22d11287d011697a6b09331bd96fa5github.com
No excerpt available.
Exploitgithub.comMar 11, 2026, 2:16 AM - https://cwe.mitre.org/data/definitions/862.htmlcwe.mitre.org
No excerpt available.
Technical Descriptioncwe.mitre.orgMar 11, 2026, 2:16 AM
Exploit code
Public exploit repository references
Public PoC repositories are third-party, potentially unsafe artifacts. Treat their code as untrusted and use it only on authorized systems in an isolated, least-privilege environment. cvebuzz does not execute the code or verify that an exploit works.
0 repository references · best confidence N/A · max 0 stars
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