Vulnerability in Mailchimp for WordPress Plugin Allows Unauthenticated Shortcode Execution
CVE-2026-118166

4.8MEDIUM

Key Information:

Vendor

WordPress
Status
Mc4WP: Mailchimp For WordPress
Vendor
CVE Published:
6 November 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-118166?

The MC4WP: Mailchimp for WordPress plugin prior to version 4.15.0 is vulnerable to a code injection flaw. This issue arises when request-derived values in dynamic content tags are processed as shortcodes, which allows unauthenticated users to execute arbitrary shortcodes with attributes specified by the attacker. This vulnerability primarily affects sites that embed forms using blocks, rather than the classic shortcode method, and requires the inclusion of a request-derived tag by the site owner.

Affected Version(s)

MC4WP: Mailchimp for WordPress 0 < 4.15.0

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-118166 - Proof of Concept

References

https://wpscan.com/vulnerability/a8b2a564-25ae-4ed8-9c2c-...
exploitvdb-entrytechnical-description

CVSS V3.1

Score:
4.8
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
High
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

Jakub Herman
WPScan
.