6.1Medium

CVE-2026-87917

The MC4WP: Mailchimp for WordPress plugin for WordPress is vulnerable to Reflected Cross-Site Scripting via 'data' Dynamic Content Tag in all versions up to, and including, 4.14.0 due to insufficient input sanitization and output escaping. This makes it possible for unauthenticated attackers to inject arbitrary web scripts in pages that execute if they can successfully trick a user into performing an action such as clicking on a link.

What this means for your business

An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.

What to do

1Ask your IT team or provider whether any of your systems use the affected product.
2If you do, follow the vendor's guidance. No patch reference has been published yet.

Not sure if your company is exposed?

Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.

Check if you’re exposed Book a call

Scoring

CVSS: 6.1 (v3.1)
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Weakness: CWE-79
Assigned by: security@wordfence.com

Dates

Published: 2026-09-19
Last modified: 2026-09-19
Sources: NVD

What this means for your business

What to do

Not sure if your company is exposed?

Scoring

Dates

References