WordPress security changelog
HIGH CVE-2026-65513 Deferred

Simply Schedule Appointments permits unauthenticated cross-site scripting

An unauthenticated visitor can submit attacker-controlled content that Simply Schedule Appointments 1.6.12.10 and earlier renders without sufficient output encoding.

CVE / CNA score 7.1 CVSS 3.1 · audit@patchstack.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Simply Schedule Appointments
Plugin slug
simply-schedule-appointments
Affected
n/a through 1.6.12.10
Safe version
1.6.12.11
Published
Aug 06, 2026
Weakness
CWE-79 — Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

This CVE was published Aug 06, 2026 and is one of 38 known issues for this plugin.

Update, patch or deactivate.

Update Simply Schedule Appointments to 1.6.12.11 or later.

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

Unauthenticated Cross Site Scripting (XSS) in Simply Schedule Appointments <= 1.6.12.10 versions.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:L

Primary and upstream sources