Authorization bypass in croixhaug Simply Schedule Appointments
Key facts
- Attack vector
- Network
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Security bypass
- Confidentiality · integrity · availability
- High · None · None
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-639.
Summary
The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.6.12.10 via the ssa_past_appointments due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with contributor-level access and above, to access appointment records belonging to arbitrary users and harvest the per-appointment ownership tokens (32-character hashes) embedded in the rendered HTML, which can then be used without any authentication to read or modify those appointments including full customer PII such as name, email, phone number, and private notes. The /wp-json/ssa/v1/render-shortcode REST endpoint is registered unconditionally on rest_api_init regardless of whether the Divi theme is installed, and its permission callback only requires current_user_can('edit_posts'), meaning any Contributor-level account is sufficient to trigger this entire exploit chain.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-13358
- 2026-10-03 Alias added: GHSA-w9gm-5x7r-8v42
References
Other 12
- https://www.wordfence.com/threat-intel/vulnerabilities/id/5dbe5094-d255-46b1-9e8e-9c48cd74e8a2?source=cve
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.4/includes/class-shortcodes.php#L781
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.4/includes/class-divi.php#L237
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.4/includes/class-divi.php#L254
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.4/includes/class-appointment-model.php#L1936
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.4/includes/class-db-model.php#L325
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.0/includes/class-shortcodes.php#L781
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.0/includes/class-divi.php#L237
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.0/includes/class-divi.php#L254
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.0/includes/class-appointment-model.php#L1936
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.11.0/includes/class-db-model.php#L325
- https://plugins.trac.wordpress.org/changeset?reponame=&old=3617759%40simply-schedule-appointments&new=3617759%40simply-schedule-appointments
More croixhaug vulnerabilities
- TI-2026-46678 WordPress Simply Schedule Appointments plugin <= 1.6.12.10 - SQL Injection vulnerability CVSS 3.1CRITICAL 9.3
- TI-2026-28467 WordPress Simply Schedule Appointments plugin <= 1.6.9.27 - SQL Injection vulnerability CVSS 3.1CRITICAL 9.3
- TI-2026-06865 Appointment Booking Calendar <= 1.6.11.8 - Unauthenticated SQL Injection via 'append_where_sql' Parameter CVSS 3.1HIGH 7.5
- TI-2026-62275 Missing authorization in croixhaug Simply Schedule Appointments CVSS 3.1HIGH 7.5
- TI-2026-58265 WordPress Simply Schedule Appointments plugin <= 1.6.12.23 - Cross Site Request Forgery (CSRF) vulnerability CVSS 3.1HIGH 8.8
- TI-2026-30684 WordPress Simply Schedule Appointments plugin < 1.6.11.2 - Sensitive Data Exposure vulnerability CVSS 3.1HIGH 7.5
Sources
- CVE-2026-13358 · CVE Program
- CVE-2026-13358 · NVD
- FIRST EPSS
- GHSA-w9gm-5x7r-8v42 · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences