Advanced Custom Fields: Extended <= 0.9.2.7 - Missing Authorization to Unauthenticated Data Exposure via Multiple AJAX Endpoints
Summary
| CVE | CVE-2026-2839 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-10-28 07:16:48 UTC |
| Updated | 2026-10-28 13:46:33 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 5.3 MEDIUM from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Problem Types: CWE-862 | CWE-862 CWE-862 Missing Authorization
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Primary | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
| 3.1 | CNA | DECLARED | 5.3 | MEDIUM | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
LowIntegrity
NoneAvailability
NoneCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Hwk-fr | Advanced Custom Fields Extended | affected 0.9.2.7 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/browser/acf-extended/trunk/includes/fields/field-advanced-lin... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/acf-extended/trunk/includes/fields/field-flexible-con... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset/3754818 | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/9954ef37-bae0-48fb-9654-ff547... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/changeset/3516027 | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/acf-extended/trunk/includes/fields/field-flexible-con... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/acf-extended/trunk/includes/fields/field-advanced-lin... | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Jay (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-02-19T23:05:23.000Z | Vendor Notified |
| CNA | 2026-10-27T00:00:00.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.