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Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin <= 1.6.11.5 — Unauthenticated Denial of Service

CVE-2026-7493Published · Updated

Action summary

Affected: ≤1.6.11.5Update to 1.6.11.7 or newer

All remediation steps
Severity
Medium5.3
CVSS
5.3
CVSS 3.1 · CNA (Wordfence)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
What does this vector mean?
AV:N Attack vector
Network
AC:L Attack complexity
Low
PR:N Privileges required
None
UI:N User interaction
None
S:U Scope
Unchanged
C:N Confidentiality
None
I:N Integrity
None
A:L Availability
Low
Weakness
CWE-400 Uncontrolled Resource Consumption
Required access
No account needed
Exploit prediction (EPSS)
No score
CISA KEV
Not listed

Am I affected?

Simply Schedule Appointments simply-schedule-appointments

  1. Affected≤ 1.6.11.5
  2. Patched in1.6.11.7

Update to 1.6.11.7 or newer.

You are affected if you run ≤ 1.6.11.5. Version 1.6.11.7 and later are not affected by this issue.

  • Check your version: in wp-admin go to Plugins → Installed Plugins and read the version under Simply Schedule Appointments.
  • No admin access? Run a passive check of your site. It reads public files only.
  • No account is needed to exploit this. Treat any exposed site on an affected version as at risk.

What to do

  1. Update to version 1.6.11.7, or a newer patched version
  2. Rotate administrator passwords and application secrets if the site ran a vulnerable version while publicly reachable.
  3. Watch Simply Schedule Appointments to get an email when the next vulnerability is published.

Advisory

Source description from Wordfence Intelligence, credited to lucky_buddy.

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to denial of service in all versions up to, and including, 1.6.11.5. This is due to a publicly accessible REST API endpoint (/wp-json/ssa/v1/async) that calls PHP's sleep() function on a user-supplied delay parameter without any rate limiting. This makes it possible for unauthenticated attackers to exhaust PHP worker processes, denying access to the site to legitimate users.

Exploits & references

Proof-of-concept & detection

No public proof-of-concept or detection template is known for this vulnerability.

Advisories & patches

More in Simply Schedule Appointments

All 52
More vulnerabilities in Simply Schedule Appointments
SeverityVulnerabilityCVEPublished
Medium5.3Missing Authorization
≤1.6.13.0Update to 1.6.13.4
CVE-2026-125437
High7.2Unauthenticated Stored Cross-Site Scripting
≤1.6.12.35Update to 1.6.12.37
CVE-2026-110382
Medium4.3Authenticated (Contributor+) Insecure Direct Object Reference
≤1.6.12.35Update to 1.6.12.37
CVE-2026-110381
High7.2Unauthenticated Stored Cross-Site Scripting via 'status' Parameter via /wp-json/ssa/v1/appointments/{id}
≤1.6.12.35Update to 1.6.12.37
CVE-2026-104000
Medium5.3Incorrect Authorization to Unauthenticated Sensitive Field Modification via Appointment Public Token
≤1.6.11.11Update to 1.6.12.0
CVE-2026-6723

Timeline

  1. CVE published

    Severity medium, CVSS 5.3

  2. Record last updated

Sources & licenses

Wordfence record
Vulnerability data
Wordfence Intelligence. [object Object] Licensed under the CC BY-SA 4.0.
CVE® identifiers
[object Object]. Used under the CVE Program. CVE® is a registered trademark of The MITRE Corporation.
CVSS / CWE
National Vulnerability Database (NVD), shown unmodified. This product uses the NVD API but is not endorsed or certified by the NVD.
VulnCrest content
Summary, remediation guidance and page layout © VulnCrest. Not sourced from NVD.

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