WordPress security changelog
MEDIUM CVE-2026-4066 Deferred

Smart Custom Fields: A security weakness

Smart Custom Fields is affected by a security weakness. Exploitation requires at least contributor-level access. The resulting impact depends on how the affected component exposes the vulnerable operation. The published affected range is <= 5.0.6.

CVE / CNA score 4.3 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Smart Custom Fields
Plugin slug
smart-custom-fields
Affected
<= 5.0.6
Safe version
> 5.0.6
Published
Mar 23, 2026
Weakness
CWE-862 — Missing Authorization

This CVE was published Mar 23, 2026 and is one of 4 known issues for this plugin.

Update, patch or deactivate.

Update Smart Custom Fields to a release after 5.0.6, or disable and remove it until a fixed version is available.

A safe version is available, so updating to that version or later is the preferred remediation. If an immediate update is not practical, consider a targeted application patch or temporarily restricting the affected functionality.

Deactivate only when warranted by your risk profile, or when advised by your hosting provider in the limited circumstances where the vulnerability cannot otherwise be mitigated. If you’re unsure which action is appropriate, contact Fused or your hosting provider for guidance.

Technical 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.

CVE / CNA vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N

Primary and upstream sources