PT-2026-64839 · WordPress · Simply Schedule Appointments

CVE-2026-13400 · Published 2026-07-27 · Updated 2026-07-27

Positive Technologies (AI Summary)

CVSS v3.1

6.1

Medium

Base vector

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

Name of the Vulnerable Software and Affected Versions Simply Schedule Appointments versions prior to 1.6.12.4

Description An unauthenticated Stored Cross-Site Scripting issue exists due to a sanitization-ordering defect. The rendered notification content is decoded back into live HTML after passing through the wp kses post() filter, allowing a double-encoded payload to bypass intake filters and execute as an active element during rendering.

Recommendations Update Simply Schedule Appointments to version 1.6.12.4 or later.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-13400

Affected Products

Simply Schedule Appointments

References · 3

• 🔥 https://wpscan.com/vulnerability/501b2929-3216-4587-8124-088fd51becf1 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-13400 · Security Note
• https://t.me/CVEtracker/61295 · Telegram Post