What’s Vulnerable › Vulnerabilities

CVE-2026-4066: Smart Custom Fields <= 5.0.6 - Missing Authorization to Authenticated (Contributor+) Sensitive Information Exposure via Relational Post Search

• Severity: medium (CVSS 4.3 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.3% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-03-23 · updated 2026-06-17
• Weakness: CWE-862

Description

The Smart Custom Fields plugin for WordPress is vulnerable to unauthorized access of data due to a missing capability check on the relational_posts_search() function in all versions up to, and including, 5.0.6. This makes it possible for authenticated attackers, with Contributor-level access and above, to read private and draft post content from other authors via the smart-cf-relational-posts-search AJAX action. The function queries posts with post_status=any and returns full WP_Post objects including post_content, but only checks the generic edit_posts capability instead of verifying whether the requesting user has permission to read each individual post.

Affected products

• inc2734 Smart Custom Fields: through 5.0.6

References

• https://plugins.trac.wordpress.org/browser/smart-custom-fields/trunk/classes/fields/class.field-related-posts.php#L101
• https://plugins.trac.wordpress.org/browser/smart-custom-fields/trunk/classes/fields/class.field-related-posts.php#L143
• https://plugins.trac.wordpress.org/browser/smart-custom-fields/trunk/classes/fields/class.field-related-posts.php#L78
• https://plugins.trac.wordpress.org/changeset?sfp_email=&sfph_mail=&reponame=&new=3485210%40smart-custom-fields%2Ftrunk&old=3416964%40smart-custom-fields%2Ftrunk&sfp_email=&sfph_mail=#file2
• https://www.wordfence.com/threat-intel/vulnerabilities/id/87f52e3a-e414-4f47-b46c-e3811e76744b?source=cve

Get alerted when CVE-2026-4066 or the next vulnerability affects your stack