Single Mailchimp: Cross-site scripting
Single Mailchimp is affected by cross-site scripting. Exploitation requires at least contributor-level access. Injected script can execute in the affected site's origin when the vulnerable output is viewed. The published affected range is <= 1.4.
- Component
- Single Mailchimp
- Plugin slug
single-mailchimp- Affected
- <= 1.4
- Safe version
> 1.4- Published
- May 27, 2026
This CVE was published May 27, 2026 and is one of 1 known issue for this plugin.
Update, patch or deactivate.
Update Single Mailchimp to a release after 1.4, or disable and remove it until a fixed version is available.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.
Technical 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.
CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N