CVE-2026-8868

Single Mailchimp <= 1.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes

Published May 27, 2026 CVSS 3.1 · 6.4 Medium EPSS < 1% KEV · Not listed
Description
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Jonathan-robrecht
Jonathan-robrecht single Mailchimp
Wordpress
Wordpress wordpress
Vendors & Products Jonathan-robrecht
Jonathan-robrecht single Mailchimp
Wordpress
Wordpress wordpress
Type Values Removed Values Added
Description 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.
Title Single Mailchimp <= 1.4 - Authenticated (Contributor+) Stored Cross-Site Scripting via Shortcode Attributes
Weaknesses CWE-79
References
Metrics cvssV3_1

{'score': 6.4, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
Wordfence
Published
Updated
May 27, 2026, 10:40 AM
Reserved
May 18, 2026, 8:18 PM
Status
Deferred
Published
May 27, 2026, 7:16 AM
Modified
Jun 17, 2026, 11:04 AM