How severe is CVE-2024-4288?

Medium severity. CVSS v3 base score is 6.4 out of 10.

XSS in Croixhaug Appointment Booking Calendar — Simply Schedule Appointments Plugin

CVE-2024-4288

The Appointment Booking Calendar — Simply Schedule Appointments Booking Plugin plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the ‘link’ parameter in versions up to, and including, 1.6.7.14 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level permissions and above, to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.

Vulnerability class: XSS (Cross-Site Scripting)

Published 2024-05-16 · last modified 2026-06-17.

CVSS v3 metric

CVSS v3 base score 6.4 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N.

EPSS exploit prediction

EPSS: 0.003 (22.7th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 23rd percentile — 22.7% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000

Affected products

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.wordfence.com/threat-intel/vulnerabilities/id/84262b4a-a662-4aaf-9eae-f5cca… (Third Party Advisory)
plugins.trac.wordpress.org/browser/simply-schedule-appointments/trunk/includes/… (Product)
plugins.trac.wordpress.org/changeset/3087297/ (Patch)

Frequently asked questions

What is CVE-2024-4288?: CVE-2024-4288 is a medium-severity vulnerability in Croixhaug Appointment Booking Calendar — Simply Schedule Appointments Plugin, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2024-05-16.
How severe is CVE-2024-4288?: Medium severity. CVSS v3 base score is 6.4 out of 10.