What is CVE-2024-3559?

CVE-2024-3559 is a medium-severity vulnerability in Custom Field Suite Project, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2024-06-12.

How severe is CVE-2024-3559?

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

XSS in Custom Field Suite Project

CVE-2024-3559

The Custom Field Suite plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the the 'cfs[post_content]' parameter versions up to, and including, 2.6.7 due to insufficient input sanitization and output escaping. This makes it possible for authenticated attackers, with contributor-level access 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 2024-06-12 · 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 (24.0th percentile), scored 2026-09-29.

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 24th percentile — 24.0% 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

Custom Field Suite Project
Mgibbs189 Custom Field Suite — versions 0

Weakness classification (CWE)

CWE-79 — Cross-site Scripting

References

www.wordfence.com/threat-intel/vulnerabilities/id/56d8af3b-6c00-49ed-872a-64f7b… (Third Party Advisory)
plugins.trac.wordpress.org/browser/custom-field-suite/trunk/includes/form.php (Product)
plugins.trac.wordpress.org/browser/custom-field-suite/trunk/includes/api.php (Product)

Frequently asked questions

What is CVE-2024-3559?: CVE-2024-3559 is a medium-severity vulnerability in Custom Field Suite Project, classified under Cross-site Scripting. CVSS score: 6.4/10. Published 2024-06-12.
How severe is CVE-2024-3559?: Medium severity. CVSS v3 base score is 6.4 out of 10.