MailChimp Forms by MailMunch <= 3.2.7 - Missing Authorization to Authenticated (Subscriber+) MailMunch Integration Takeover via 'sign_in' AJAX Action

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-7520
StatePUBLISHED
AssignerWordfence
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-08-05 08:16:44 UTC
Updated2026-08-12 21:00:37 UTC
DescriptionThe MailChimp Forms by MailMunch plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the `sign_in()` and `sign_up()` AJAX handlers in all versions up to, and including, 3.2.7. This makes it possible for authenticated attackers, with Subscriber-level access and above, to relink the site's MailMunch integration to an attacker-controlled MailMunch account by submitting attacker-supplied credentials. Once relinked, all subscriber data captured by the plugin's forms is delivered to the attacker, and the forms/landing pages rendered on the site are pulled from the attacker's MailMunch account.

Risk And Classification

Primary CVSS: v3.1 8.1 HIGH from [email protected]

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

EPSS: 0.002700000 probability, percentile 0.190060000 (date 2026-08-12)

Problem Types: CWE-862 | CWE-862 CWE-862 Missing Authorization

VersionSourceTypeScoreSeverityVector
3.1[email protected]Secondary8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
3.1CNADECLARED8.1HIGHCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

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

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Mailmunch Mailmunch Forms For Mailchimp affected 3.2.7 semver Not specified

References

ReferenceSourceLinkTags
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.2.7/admin/class-m... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.2.7/admin/class-m... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/trunk/admin/class-mailch... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.2.7/includes/clas... [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.2.7/includes/clas... [email protected] plugins.trac.wordpress.org
www.wordfence.com/threat-intel/vulnerabilities/id/c9d00ee8-b9df-4044-a5e2-32039... [email protected] www.wordfence.com
plugins.trac.wordpress.org/changeset [email protected] plugins.trac.wordpress.org
plugins.trac.wordpress.org/browser/mailchimp-forms-by-mailmunch/tags/3.2.7/includes/clas... [email protected] plugins.trac.wordpress.org
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Vendor Comments And Credit

Discovery Credit

CNA: t0ann9uy3n (en)

Additional Advisory Data

SourceTimeEvent
CNA2026-08-04T18:41:47.000ZDisclosed

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