# CVE-2026-39447: NSquared Simply Schedule Appointments unauthenticated XSS

Source: https://junglewise.ai/threats/cve-2026-39447-nsquared-simply-schedule-appointments-unauthenticated-xss  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-15. Updated: 2026-06-15  
License: CC BY 4.0 with a link back

CVE-2026-39447 · Severity: high · CVSS 7.1 · Published 2026-06-15

Simply Schedule Appointments is a WordPress plugin used by businesses to manage client bookings and scheduling. A security flaw in this plugin allows an unauthenticated attacker to inject malicious scripts into the website. If a site visitor or administrator interacts with a specially crafted link or page, the attacker could steal session information, redirect users to malicious sites, or perform unauthorized actions on behalf of the user.

## Quick answers

**Is CVE-2026-39447 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-39447 being exploited in the wild.

**How severe is CVE-2026-39447?** High severity, with a CVSS score of 7.1, published 15 June 2026.

**Which products and versions are affected?** NSquared Simply Schedule Appointments <= 1.6.10.6.

**Is there a fix for CVE-2026-39447?** A patch was published on 2026-05-28: Patch released in version 1.6.11.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2026-39447 attacked?** It is attacked over the network, in a web application.

**Am I affected by CVE-2026-39447?** Check whether anything you run is named in the advisory. 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

A Reflected Cross-Site Scripting (XSS) vulnerability exists in the Simply Schedule Appointments plugin for WordPress due to improper neutralization of user-supplied input during web page generation (CWE-79). The vulnerability affects versions up to and including 1.6.10.6. An unauthenticated remote attacker can exploit this by tricking a user into clicking a malicious link or visiting a crafted page. Successful exploitation allows the execution of arbitrary JavaScript in the context of the victim's browser session, which can lead to session hijacking or unauthorized administrative actions if the victim is an authenticated administrator. The issue is resolved in version 1.6.11.0.

## Affected products

- NSquared Simply Schedule Appointments <= 1.6.10.6

## Timeline

- 2026-04-06: other: Reported by researcher devploit
- 2026-05-28: advisory: Initial advisory published by Patchstack
- 2026-05-28: patched: Patch released in version 1.6.11.0
- 2026-06-15: disclosed: CVE published to NVD

## References

- [https://patchstack.com/database/wordpress/plugin/simply-schedule-appointments/vulnerability/wordpress-simply-schedule-appointments-plugin-1-6-10-6-cross-site-scripting-xss-vulnerability?_s_id=cve](https://patchstack.com/database/wordpress/plugin/simply-schedule-appointments/vulnerability/wordpress-simply-schedule-appointments-plugin-1-6-10-6-cross-site-scripting-xss-vulnerability?_s_id=cve)