Auth bypass in Mc4wp: Mailchimp For WordPress

CVE-2026-118167

The MC4WP: Mailchimp for WordPress plugin before 4.15.0 does not validate that the Mailchimp audience a sign-up form or bundled integration subscribes a visitor to matches the audience configured by the site owner, allowing unauthenticated visitors to subscribe arbitrary email addresses to any other audience in the site's connected Mailchimp account.

Vulnerability class: Broken Access Control

Published · last modified .

CVSS v3 metric

CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N.

EPSS exploit prediction

EPSS: 0.002 (11.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 12th percentile — 11.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

The 30-day trend appears once there are two daily scores.

Affected products

  • Mc4wp: Mailchimp For WordPress

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-118167?
CVE-2026-118167 is a medium-severity vulnerability in Mc4wp: Mailchimp For WordPress, classified under Incorrect Authorization. CVSS score: 5.3/10. Published 2026-11-06.
How severe is CVE-2026-118167?
Medium severity. CVSS v3 base score is 5.3 out of 10.