WordPress security changelog
MEDIUM CVE-2026-13358 Deferred

Simply Schedule Appointments shortcode exposes cross-user ownership tokens

Simply Schedule Appointments through 1.6.12.10 exposes /wp-json/ssa/v1/render-shortcode to any Contributor through an edit_posts permission check. Supplying ssa_past_appointments for another user's records returns appointment HTML containing 32-character ownership tokens; those tokens can then be used without authentication to read or modify the appointments, including customer name, email, phone, and private notes. The identifier parameter and token-consuming routes are not disclosed.

CVE / CNA score 6.5 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Simply Schedule Appointments
Plugin slug
simply-schedule-appointments
Affected
<= 1.6.12.10
Safe version
See mitigation notes
Published
Aug 16, 2026
Weakness
CWE-639 — Authorization Bypass Through User-Controlled Key

This CVE was published Aug 16, 2026 and is one of 38 known issues for this plugin.

What to do

Update, patch or deactivate.

No fixed release is identified in the authoritative record. Update when a confirmed patch is available; until then, restrict Contributors or disable the affected shortcode route, rotate appointment tokens where possible, and assess customer PII exposure and modification. The official upstream changelog lists version 1.6.12.17, which is newer than the published affected range. Its changelog does not clearly confirm this specific fix, so it is not counted as a known-safe release.

No confirmed safe version is listed. Consider a vendor-supported patch or temporarily restricting the affected functionality while you assess the risk.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Source record

Technical description

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.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N

References

Primary and upstream sources