PatchSiren cyber security CVE debrief
CVE-2026-1856 creavi CVE debrief
The Appointment Booking Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via custom booking field labels in all versions up to, and including, 1.4.4. This vulnerability is due to insufficient input sanitization and output escaping, allowing authenticated attackers with Author-level access and above to inject arbitrary web scripts. These scripts will execute whenever a user accesses an injected page, potentially impacting users and requiring review of compensating controls.
- Vendor
- creavi
- Product
- Creavi Appointment Booking Calendar
- CVSS
- MEDIUM 6.4
- CISA KEV
- Not listed in stored evidence
- Original CVE published
- 2026-06-19
- Original CVE updated
- 2026-06-22
- Advisory published
- 2026-06-19
- Advisory updated
- 2026-06-22
Who should care
Authenticated attackers with Author-level access and above could inject arbitrary web scripts, impacting users accessing injected pages. Operators of WordPress deployments using the Appointment Booking Calendar plugin should review their exposure and consider security measures to protect against potential attacks.
Technical summary
The Appointment Booking Calendar plugin for WordPress is vulnerable to Stored Cross-Site Scripting via custom booking field labels in all versions up to, and including, 1.4.4. This is due to insufficient input sanitization and output escaping, allowing authenticated attackers with Author-level access and above to inject arbitrary web scripts. These scripts will execute whenever a user accesses an injected page, potentially impacting users and requiring review of compensating controls and security measures.
Defensive priority
Medium priority due to CVSS score of 6.4 and potential impact on users accessing injected pages, requiring review of security measures and compensating controls.
Recommended defensive actions
- Update to a patched version of the Appointment Booking Calendar plugin
- Restrict access to the plugin's settings and functionality to trusted users only
- Monitor for suspicious activity and injected scripts on affected pages
- Consider implementing additional security measures such as Web Application Firewall (WAF) rules to detect and prevent similar attacks
- Review compensating controls for exposed systems while remediation is scheduled and verified
- Check relevant monitoring, detection, and logs for exposed assets that need extra review
- Track exceptions, retest remediated assets, and close the item only after evidence is documented
Evidence notes
CVE-2026-1856 was published on 2026-06-19T06:17:01.807Z and last modified on 2026-06-22T19:16:50.793Z. The NVD entry is currently Deferred. Evidence is limited to CVE and NVD details. Defenders should verify affected product deployments and review official advisories for scope and severity.
Official resources
AI-assisted PatchSiren debrief based on the supplied source corpus. The CVE record was published on 2026-06-19T06:17:01.807Z and has not been modified since then. The NVD entry is currently Deferred.