# CVE-2026-66606: SmartSMTP unauthenticated cross-site scripting

Source: https://junglewise.ai/threats/cve-2026-66606-smartsmtp-unauthenticated-cross-site-scripting  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-08-20. Updated: 2026-09-25  
License: CC BY 4.0 with a link back

CVE-2026-66606 · Severity: high · CVSS 7.1 · Published 2026-08-20

SmartSMTP is a WordPress plugin used for email functionality on websites. An unauthenticated attacker can inject malicious scripts into affected sites through cross-site scripting (XSS), allowing them to steal visitor data, hijack accounts, or compromise website visitors without requiring the attacker to have admin access.

Vendors: [ThemeGrill](https://junglewise.ai/threats/vendors/themegrill).

## Quick answers

**Is CVE-2026-66606 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-66606 being exploited in the wild.

**How severe is CVE-2026-66606?** High severity, with a CVSS score of 7.1, published 20 August 2026.

**Which products and versions are affected?** ThemeGrill SmartSMTP <=1.2.0.

**Is there a fix for CVE-2026-66606?** A patch was published on 2026-08-19: Version 1.2.1 or later available Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-66606 attacked?** It is attacked over the network, in a software library.

**Am I affected by CVE-2026-66606?** Check whether you run ThemeGrill SmartSMTP at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

This is a stored or reflected cross-site scripting (XSS) vulnerability in the SmartSMTP WordPress plugin affecting versions 1.2.0 and earlier. The vulnerability requires an unauthenticated attacker to craft a malicious input, but successful exploitation requires user interaction (e.g., a privileged user clicking a malicious link or visiting a crafted page). The attacker can inject arbitrary JavaScript that executes in victims' browsers, enabling data theft or account hijacking. A patch is available in version 1.2.1 and later.

## Affected products

- ThemeGrill SmartSMTP <=1.2.0

## Timeline

- 2026-08-19: disclosed
- 2026-08-19: patched: Version 1.2.1 or later available

## References

- [https://wordpress.org/plugins](https://wordpress.org/plugins)
- [https://patchstack.com/database/wordpress/plugin/smart-smtp/vulnerability/wordpress-smartsmtp-plugin-1-2-0-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/smart-smtp/vulnerability/wordpress-smartsmtp-plugin-1-2-0-cross-site-scripting-xss-vulnerability?_s_id=cve)