Simply Schedule Appointments WordPress plugin: Broken access control
Summary
The WordPress plugin Simply Schedule Appointments up to and including version 1.6.13.0 contains a missing authorization flaw (CWE-862) that allows access to functions or data that should be restricted. Per the CVSS vector, an unauthenticated remote attacker could read limited data, with no impact on integrity or availability. Booking data may contain customer personal data, so the exposure is relevant for data protection. Exploitation is not known, and the exposed resource is not described in the sources.
Affected
- NSquared Simply Schedule Appointments (WordPress plugin) versions up to and including 1.6.13.0
- Versions 1.6.13.1 to 1.6.13.3: status unverified
Fixed in
- Version 1.6.13.4 (first unaffected version according to the CVE record and Patchstack)
Workaround
- No vendor workaround documented.
- If an update must be delayed, restrict access to the plugin's REST endpoints at the web application firewall or reverse proxy. This is generic advice and not a documented fix; the affected endpoints are unknown.
Exploitation
- Not known to be exploited.
- No public proof of concept found for this CVE.
- CISA SSVC: exploitation none, automatable yes, technical impact partial.
- A public PoC exists for a different plugin flaw (CVE-2026-94074), which does not indicate exploitation of this CVE.
Our recommendation
- Inventory WordPress sites that run this plugin and record the installed version.
- Update to version 1.6.13.4 or later and verify the installed version afterwards on the official wordpress.org listing.
- If the update was delayed, review booking data and REST access logs on exposed sites.
- Check NVD and the Patchstack advisory again once NVD analysis is complete.
Public exploits
PoC-in-GitHub, Metasploit and Exploit-DB list nothing for this CVE.
Research sources
- CVE Record CVE-2026-125437 www.cve.org
- Patchstack advisory patchstack.com
- OffSeq radar entry radar.offseq.com
- WordPress.org plugin page wordpress.org
- WPScan vulnerability entry wpscan.com
Researched and written up in English and German by an AI (Claude by Anthropic) based on NVD, CISA, EPSS and the sources listed. The vendor information is authoritative. Researched on 11 Nov 2026, 17:45.
Original description (NVD)
Missing Authorization vulnerability in NSquared Simply Schedule Appointments simply-schedule-appointments allows Exploiting Incorrectly Configured Access Control Security Levels.This issue affects Simply Schedule Appointments: from n/a through 1.6.13.0.
Sources
The tracker combines official, freely usable data sources – updated continuously:
- NVD (NIST) – CVEs, rating (CVSS), affected products
- CISA KEV – vulnerabilities confirmed by CISA as actively exploited
- CISA Vulnrichment – CISA assessment (SSVC) in the official CVE record
- FIRST EPSS – probability of exploitation
- Microsoft MSRC – Patch Tuesday: vulnerabilities, severity, updates
- PoC-in-GitHub – public proof-of-concept repositories
- Metasploit (Rapid7) – modules of the Metasploit Framework
- Exploit-DB (OffSec) – archive of public exploits (links only)
- Patch days: official vendor pages (linked per vendor) (Vendor patch days)
This product uses data from the NVD API but is not endorsed or certified by the NVD. EPSS data © FIRST.org.
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