MailMunch MailChimp Forms by MailMunch Plugin up to 3.2.7 on WordPress AJAX sign_in/sign_up improper authorization

Summaryinfo

A vulnerability identified as critical has been detected in MailMunch MailChimp Forms by MailMunch Plugin up to 3.2.7. Affected is the function sign_in/sign_up of the component AJAX Handler. This manipulation causes improper authorization. This vulnerability appears as CVE-2026-7520. The attack may be initiated remotely. There is no available exploit.

Detailsinfo

A vulnerability was found in MailMunch MailChimp Forms by MailMunch Plugin up to 3.2.7. It has been declared as critical. Affected by this vulnerability is the function sign_in/sign_up of the component AJAX Handler. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

The 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.

It is possible to read the advisory at wordfence.com. This vulnerability is known as CVE-2026-7520 since 04/30/2026. The exploitation appears to be easy. The attack can be launched remotely. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 08/05/2026). The attack technique deployed by this issue is T1548.002 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-53287). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• MailMunch

Name

• MailChimp Forms by MailMunch Plugin

Version

• 3.2.0
• 3.2.1
• 3.2.2
• 3.2.3
• 3.2.4
• 3.2.5
• 3.2.6
• 3.2.7

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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