Easy Appointments: Predictable appointment confirmation and cancellation tokens
An unauthenticated attacker who knows or can guess an appointment's creation timestamp can derive email confirmation or cancellation tokens because they use a hard-coded salt. The export does not disclose the token parameter or derivation function. Affected versions reported by the CNA: < 4.0.2.2. The export identifies 4.0.2.2 as fixed.
- Component
- Easy Appointments
- Plugin slug
easy-appointments- Affected
- < 4.0.2.2
- Safe version
4.0.2.2- Published
- Sep 18, 2026
This CVE was published Sep 18, 2026 and is one of 26 known issues for this plugin.
Update, patch or deactivate.
The authoritative export identifies 4.0.2.2 as fixed. Update to that release or a later supported version. Generate cryptographically random, appointment- and action-bound tokens with expiry instead of deriving authorization from a public constant and predictable timestamp.
A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.
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.
Technical description
The Easy Appointments WordPress plugin before 4.0.2.2 does not use an unguessable token to authorize its mail-link appointment cancellation and confirmation action, deriving the token from a hardcoded source-embedded salt and the appointment's creation timestamp, so unauthenticated attackers who know or guess that timestamp can cancel or confirm arbitrary appointments.
CVE / CNA vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:L