WordPress security changelog
CRITICAL CVE-2026-8809 Deferred

Advanced Custom Fields: Extended: Privilege escalation or authentication bypass

Advanced Custom Fields: Extended is affected by privilege escalation or authentication bypass. The vulnerable path is reachable without authentication. A successful request can grant permissions or access that the caller should not possess. The published affected range is <= 0.9.2.5.

CVE / CNA score 9.8 CVSS 3.1 · security@wordfence.com
NVD score Pending NVD has not published its own CVSS assessment.
Component
Advanced Custom Fields: Extended
Plugin slug
acf-extended
Affected
<= 0.9.2.5
Safe version
> 0.9.2.5
Published
May 28, 2026
Weakness
CWE-269 — Improper Privilege Management

This CVE was published May 28, 2026 and is one of 4 known issues for this plugin.

What to do

Update, patch or deactivate.

Update Advanced Custom Fields: Extended to a release after 0.9.2.5, 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.

Source record

Technical description

The Advanced Custom Fields: Extended plugin for WordPress is vulnerable to Privilege Escalation via Validation Bypass in all versions up to and including 0.9.2.5. The vulnerability exists due to the after_validate_save_post() function unconditionally trusting the attacker-controlled _acf_post_id POST parameter — with no authentication or integrity verification — to select a cleanup branch that silently discards all validation errors not prefixed with acfe:. This makes it possible for unauthenticated attackers to suppress both the role allow-list validation error added by acfe_field_user_roles::validate_front_value() and the administrator-role capability guard error added by acfe_module_form_action_user::validate_action(), causing wp_insert_user() to execute with an attacker-supplied administrator role argument and resulting in the creation of a new administrator-level user account. Exploitation requires the target site to expose a public ACFE frontend form configured with a Create User action that maps a role field.

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

References

Primary and upstream sources