CVE-2026-111727
Tenable Plugin
Checking the public Tenable catalog…
AI Threat Summary
CVE-2026-111727 is a moderate vulnerability with a CVSS score of 6.4 affecting the target software. Threat hunters should monitor for exploit attempts and apply vendor patches immediately.
Description
The Appointment Booking Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the 'vs_text_submitbtn' parameter in all versions up to, and including, 1.4.05 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with subscriber-level access and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page. This requires the attacker to be assigned as a calendar owner, a per-user grant that any administrator can extend to users as low as Subscriber level through the plugin's calendar list screen. Exploitation by attackers with subscriber-level access and above requires that an administrator has assigned the attacker's account as owner (`conwer`) of a calendar via the plugin's calendar list screen; the plugin's UI lists all registered users regardless of role, so a Subscriber can be assigned. On a default installation, where that is not configured, the vulnerability requires attackers with editor-level access and above.
Attack Chain
Attacker scans for vulnerable versions using version banners or PoC scanners
Attacker triggers CVE-2026-111727 vulnerability with a crafted request or payload
Vulnerability exploited to perform unauthorized actions on the target system
Depending on vulnerability type, attacker achieves data access, service disruption, or code execution
MITRE ATT&CK Techniques
Indicators of Compromise
| Type | Value | Description | |
|---|---|---|---|
| user_agent | Mozilla/5.0 (compatible; exploit/1.0) |
Generic exploit scanner user agent pattern | |
| url | /api/vuln-endpoint?payload=<malicious> |
Exploit attempt against application endpoint — monitor access logs for anomalous params |
Remediation
Quick Facts
| CVE ID | CVE-2026-111727 |
| CVSS Score | 6.4 |
| Vector | CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N |
| Published | 2026-10-28 |
| Exploited | No |
| CISA KEV | No |
| PoC | Not public |
References
- https://plugins.trac.wordpress.org/browser/appointment-booki…
- https://plugins.trac.wordpress.org/browser/appointment-booki…
- https://plugins.trac.wordpress.org/browser/appointment-booki…
- https://plugins.trac.wordpress.org/browser/appointment-booki…
- https://plugins.trac.wordpress.org/browser/appointment-booki…
- https://plugins.trac.wordpress.org/changeset/3750835/appoint…
- https://plugins.trac.wordpress.org/log/appointment-booking-c…
- https://www.wordfence.com/threat-intel/vulnerabilities/id/dd…