PT-2026-43516 · Jonathan Robrecht · Single Mailchimp

Published 2026-05-27 · Updated 2026-05-27 · CVE-2026-8868

Mitre

CVSS v3.1

6.4

Medium

Base vector

AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

The Single Mailchimp plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'single-mailchimp' shortcode in all versions up to, and including, 1.4. This is due to insufficient input sanitization and output escaping on user-supplied shortcode attributes (autocomplete, label, placeholder, btn text, success msg, error msg) which are concatenated directly into HTML output by the single mailchimp() function in shortcodes.php. This makes it possible for authenticated attackers, with contributor-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-8868

Affected Products

Single Mailchimp

References · 4

• https://nvd.nist.gov/vuln/detail/CVE-2026-8868 · Security Note
• https://wordfence.com/threat-intel/vulnerabilities/id/070616c9-b6a3-43d9-a82d-5cbcffc39ad9?source=cve · Note
• https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L9 · Note
• https://plugins.trac.wordpress.org/browser/single-mailchimp/trunk/shortcodes.php#L23 · Note