CVE-2026-59523

WordPress Simply Schedule Appointments plugin <= 1.6.11.11 - Broken Access Control vulnerability

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 <= 1.6.11.11.

We have discovered 4,908 live websites that are affected by CVE-2026-59523.

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Affected Software

Product  Simply Schedule Appointments
Category Wordpress Plugins
Vulnerable Domains4,908 live websites (65% of Simply Schedule Appointments install base)
Vulnerable Versions
  • from 0 through 1.6.11.11
Vulnerable Versions Count160 versions ( 45% of all versions)



Details

  • Published - Jul 13, 2026
  • Updated - Jul 13, 2026

Credits

  • anhcd05 | Patchstack Bug Bounty Program (finder)

Website Distribution by Country

Number of websites using CVE-2026-59523
United States1,365 websites


Germany939 websites
Italy293 websites
GB245 websites
France185 websites
Netherlands178 websites
Spain138 websites
Canada135 websites
Denmark117 websites
Switzerland95 websites

Website Distribution by TLD

Number of websites using CVE-2026-59523
.com2,034 websites
.de668 websites
.it213 websites
.org171 websites
.nl157 websites
.co.uk143 websites
.net94 websites
.ch86 websites
.ca80 websites
.fr75 websites

Vulnerable Versions

Vulnerable versions are highlighted in red

Websites affected by CVE-2026-59523

Top websites that are affected by CVE-2026-59523. Please click on the "Contact us" link to get more information.
DomainCountryRankContacts
***.org United States**,***
*********.org United States**,***
*****************.org GB***,***
*******.com GB***,***
****.hu Hungary***,***
***************.com India***,***
**************.com United States***,***
***********.com United States***,***
******.***.edu United States***,***
************.hu Hungary***,***
See full domain list

FAQ

A total of 4,908 websites have been identified as vulnerable to CVE-2026-59523, based on global website indexing conducted by WebTechSurvey.
The Simply Schedule Appointments is affected by the CVE-2026-59523 vulnerability.
Simply Schedule Appointments versions up to and including 1.6.11.11 are vulnerable to CVE-2026-59523.