Easy!Appointments disable_booking_message rendered as raw HTML on public booking page — Stored XSS
Key facts
- Attack vector
- Network
- Privileges required
- High
- User interaction
- Required
- Attack complexity
- High
- Impact type
- Cross-site scripting
- Confidentiality · integrity · availability
- None · Low · None
- Fix status
- Fixed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and GitHub. Impact type from CWE-79.
Summary
Easy!Appointments is a self hosted appointment scheduler. Versions prior to 1.6.0 allow administrators to define a custom "booking disabled" message through the booking settings page. That value is stored in the `disable_booking_message` setting via a rich-text editor and later passed directly to the public `booking_message` view without escaping or sanitization. An authenticated administrator can store HTML or JavaScript in this field, enable disabled-booking mode, and trigger stored XSS in every unauthenticated visitor who opens the public booking page. Version 1.6.0 fixes the issue.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- 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
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| alextselegidis | easyappointments | before 1.6.0 | 1.6.0 | Patch available | CNA |
| — | alextselegidis/easyappointments (Packagist) | up to 1.5.2 | — | No fix listed | GHSA-996f-334j-67g7 |
- easyappointments Vendoralextselegidis Affected before 1.6.0 Fixed in 1.6.0 Patch available CNA
- alextselegidis/easyappointments (Packagist) Vendor— Affected up to 1.5.2 Fixed in — No fix listed GHSA-996f-334j-67g7
Remediation
- Fix · CNA easyappointments (alextselegidis) Fixed in 1.6.0
Timeline
- 2026-10-02 Threatist record created from CVE-2026-52838
- 2026-10-03 Alias added: GHSA-996f-334j-67g7
References
Other 4
- https://github.com/alextselegidis/easyappointments/security/advisories/GHSA-996f-334j-67g7
- https://github.com/alextselegidis/easyappointments/commit/629a0415f54f75556c17f4f5d9c77fda1fdbdeae
- https://github.com/alextselegidis/easyappointments
- https://github.com/alextselegidis/easyappointments/releases/tag/1.6.0
More alextselegidis vulnerabilities
- TI-2023-01200 Use of Hard-coded Credentials in alextselegidis/easyappointments CVSS 3.1CRITICAL 9.8
- TI-2026-70736 Easy!Appointments authorization bypass lets attackers modify bookings CVSS 4.0HIGH 8.8
- TI-2024-37956 An issue in Alex Tselegidis EasyAppointments v.1.5.0 allows a remote attacker to escalate… CVSS 3.1CRITICAL 9.8
- TI-2026-19023 CSRF Protection Bypass: Sensitive endpoints accept GET requests, enabling admin account takeover CVSS 4.0HIGH 7.4
- TI-2025-32119 alextselegidis Easy!Appointments v1.5.1 was discovered to contain a SQL injection… CVSS 3.1HIGH 8.1
- TI-2023-01980 Session Fixation in alextselegidis/easyappointments CVSS 3.1HIGH 8.8
Sources
- CVE-2026-52838 · CVE Program
- CVE-2026-52838 · NVD
- FIRST EPSS
- GHSA-996f-334j-67g7 · 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