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.
CVE-2026-4066 is a medium severity with CVSS 4.3 Sensitive Information Exposure issue affecting the Plugin Smart Custom Fields. It affects Versions up to 5.0.6 and is fixed in 5.0.7.
CVE-2026-4066 is tracked for the Plugin Smart Custom Fields as medium severity with CVSS 4.3. The affected range is Versions up to 5.0.6. Update Smart Custom Fields to 5.0.7 or newer where that version is compatible with the site.
| Software Type | Plugin |
|---|---|
| Software Slug |
smart-custom-fields
View on wordpress.org
|
| CVE | CVE-2026-4066 |
| Patched Versions |
5.0.7
|
| Affected Versions |
Versions up to 5.0.6
|
These internal links group the same WordPress plugin by CVE, issue type, severity, and patch status so operators and search engines can connect the full vulnerability cluster.
Smart Custom Fields <= 5.0.0 - Authenticated (Contributor+) Stored Cross-Site Scripting
Smart Custom Fields <= 4.2.2 - Missing Authorization to Authenticated (Subscriber+) Post Content Disclosure
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