Not a U.S. government website. NDD is an independent vulnerability database by Volerion and is not affiliated with or endorsed by NIST or NVD.

CVE-2026-13400 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

Simply Schedule Appointments is vulnerable to unauthenticated Stored Cross-Site Scripting in all versions up to and including 1.6.12.2. The root cause is a sanitization-ordering defect: the rendered notification content is decoded back into live HTML after it has already passed through the Simply Schedule Appointments WordPress plugin before 1.6.12.4's wp_kses_post() filter, so a double-encoded payload survives intake and is reintroduced as an executable element at render time.

Metrics

CVSS 3.x Severity and Vector Strings:

VolerionCVSS-B:9.3 CRITICALVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:N

CNA: CISA-ADPCVSS-B:6.1 MEDIUMVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N

References to Advisories, Solutions, and Tools

By selecting these links, you will be leaving this site. These are references gathered from the official CVE record and are not endorsed by Volerion.

URL	Source(s)	Tag(s)
https://wpscan.com/vulnerability/501b2929-3216-4587-8124-088fd51becf1/	[email protected]	AdvisoryExploitRemedy

Weakness Enumeration

CWE-ID	CWE Name	Source
CWE-79	Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')	CISA-ADP

Affected Products

Product	Versions
Simply Schedule Appointments	<= 1.6.12.2
CPE No CPEs found in CPE dictionary for this product. Remediation Upgrade: 1.6.12.4moderate effort

Change History

2 change records found show changes

Date	Action	Recorded By
Jul 27, 2026	CVE Modified	CISA-ADP
Jul 27, 2026	New CVE Received	[email protected]