CVE-2026-91109
Simply Schedule Appointments <= 1.6.12.31 - Insecure Direct Object Reference to Authenticated (Subscriber+) Sensitive Information Disclosure via 'complete_group' Parameter
- Published
- Updated
- Reserved
- Assigned by
- Wordfence
Description
The Simply Schedule Appointments plugin for WordPress is vulnerable to Insecure Direct Object Reference in all versions up to, and including, 1.6.12.31 via the 'complete_group' parameter due to missing validation on a user controlled key. This makes it possible for authenticated attackers, with subscriber-level access and above, to disclose every co-booker's private per-appointment id_token (exposed as public_token) alongside their PII (name and email address), then use each leaked token to read, overwrite arbitrary appointment meta on, or cancel the co-booker's appointment via the same REST controller. Exploitation requires the attacker to possess a valid id_token for any single appointment within the targeted group booking.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| WordfenceCNA (assigner) | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
| NVDNVD · Deferred | 3.1 | Medium6.5 | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N |
- EPSS (exploitation in 30 days)
- 0.31% · top 76% of all CVEs (6 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 6.5.
Weakness
Affected products
croixhaug · Simply Schedule Appointments
- affected ≤ 1.6.12.31
References (6)
- https://www.wordfence.com/threat-intel/vulnerabilities/id/d1cd3de2-16ca-4f95-ad6f-47cfbe00c959?source=cve (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes/class-appointment-model.php#L3160 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes/class-appointment-model.php#L1966 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes/class-appointment-model.php#L2315 (opens in a new tab)
- https://plugins.trac.wordpress.org/browser/simply-schedule-appointments/tags/1.6.12.27/includes/class-db-model.php#L348 (opens in a new tab)
- https://plugins.trac.wordpress.org/changeset/3709365/simply-schedule-appointments/trunk/includes/class-appointment-model.php (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://trackcve.app/cve/CVE-2026-91109)Record last updated .