Track vulnerabilities like this one. Sign up free to get alerted when software you use is affected.
5.3

Advanced Custom Fields: Extended allows guests to view data

CVE-2026-2839 · published 7 days ago
Summary

The Advanced Custom Fields: Extended plugin for WordPress lets anyone on the internet call hidden server functions and see internal page information, such as post titles and layout details. This happens because the plugin creates special tokens that are visible to all visitors and does not check whether the user should be allowed to use those functions. Upgrade the plugin to the latest version (or apply the vendor’s patch) and remove any old versions from your site.

What to do

The CVE record does not list a fixed version. Check the vendor's site or the advisory links below - a fix may already be released.

Affected software
VendorProductAffected versions
hwk-fr advanced custom fields: extended <= 0.9.2.7
Original advisory text
Advanced Custom Fields: Extended <= 0.9.2.7 - Missing Authorization to Unauthenticated Data Exposure via Multiple AJAX Endpoints
The Advanced Custom Fields: Extended plugin for WordPress is vulnerable to unauthorized access of data and triggering of server-side actions in all versions up to, and including, 0.9.2.7. This is due to multiple AJAX handlers registered for unauthenticated users (`wp_ajax_nopriv_*`) that fail to implement proper `current_user_can()` authorization checks. While these handlers use ACF's `acf_verify_ajax()` function to validate cryptographic nonces, the `acf_nonce` values are generated for guest users and publicly exposed in the page source of any frontend page utilizing an ACF form. This makes it possible for unauthenticated attackers to extract the guest nonce and bypass WordPress visibility permissions, leading to the unauthorized disclosure of post titles and internal Flexible Content layout structures. The vulnerability was partially patched in version 0.9.2.4.
References
Fix within
Internet-facing 14 days
Internal 60 days
  • Not known to be exploited
  • Can be exploited automatically
  • Gives an attacker partial control
Severity
5.3 Medium
Exploitation
<1% chance of attack within 30 days
Type
CWE-862Missing Authorization
Timeline
Published28 Oct 2026
Updated3 Nov 2026
First seen28 Oct 2026
Sources
CVE-2026-2839 · NVD
CVE-2026-2839 · MITRE
Track software like this
Free during beta