Quick answers
- Is CVE-2026-6286 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-6286 being exploited in the wild.
- How severe is CVE-2026-6286?
- High severity, with a CVSS score of 7.2, published 28 August 2026.
- Which products and versions are affected?
- Elfsight Amelia Booking for Appointments and Events Calendar up to and including 2.2.
- Is there a fix for CVE-2026-6286?
- No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
- How is CVE-2026-6286 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-6286?
- Check whether you run Elfsight Amelia Booking for Appointments and Events Calendar at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
Technical details
The vulnerability is a Stored Cross-Site Scripting (XSS) vulnerability arising from insufficient input validation and output encoding. The root cause is a two-stage failure: first, an authentication bypass in AddBookingCommand (Command.php line 186) skips nonce verification, allowing unauthenticated booking submissions. Second, while the plugin sanitizes customer firstName and lastName via sanitize_text_field(), this function only removes HTML tags but preserves special characters including double quotes. The injected payload then escapes into JavaScript template literals in the FullCalendar eventContent callback (redesign/dist/index.js line 199), where it is rendered via innerHTML without proper HTML entity encoding. An attacker can inject payloads such as '" onmouseover="alert(document.cookie)"' to break out of the title attribute and execute event handlers. The attack vector is network-based and requires only an unauthenticated user to craft a malicious booking; code execution occurs when an administrator hovers over the appointment on the Calendar page. A patch addressing both the authentication bypass and output encoding is recommended.
Affected products
- Elfsight Amelia Booking for Appointments and Events Calendar up to and including 2.2
Timeline
- 2026-08-28: disclosed