WordPress security changelog
CRITICAL CVE-2026-16940 Received

Custom Fields permits unauthenticated arbitrary file deletion

Custom Fields before 1.5.1 accepts an unauthenticated, user-controlled filesystem path and deletes the referenced file without constraining it to an intended directory. An attacker can delete arbitrary server files such as wp-config.php; removing critical configuration can disrupt the site and may enable takeover during recovery or reinstallation. This unscored record received deeper review because unauthenticated arbitrary file deletion is directly chainable. The CNA does not disclose the endpoint, action, parameter or deletion function.

CVE / CNA score 10.0 CVSS 3.1 · 134c704f-9b21-4f2e-91b3-4a467353bcc0
NVD score Pending NVD has not published its own CVSS assessment.
Component
Custom Fields
Plugin slug
custom-fields
Affected
< 1.5.1
Safe version
1.5.1
Published
Aug 05, 2026
Weakness
CWE-22 — Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')

This CVE was published Aug 05, 2026 and is one of 1 known issue for this plugin.

Update, patch or deactivate.

Update Custom Fields to 1.5.1 or later. Verify critical WordPress and server files against a known-good backup and investigate unexplained configuration loss if a vulnerable version was publicly reachable.

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 Custom Fields WordPress plugin before 1.5.1 does not validate a user-supplied file path before deletion, allowing unauthenticated users to delete arbitrary files on the server (such as wp-config.php), which can lead to a full site takeover.

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

Primary and upstream sources