CVE-2026-8809
CriticalCVSS 9.8Exploitation Probability (EPSS)
Elevated risk53th percentile - higher than 53% of all known CVEs
Summary
The Advanced Custom Fields: Extended plugin for WordPress up to version 0.9.2.5 is vulnerable to privilege escalation via validation bypass. The after_validate_save_post() function unconditionally trusts the attacker-controlled _acf_post_id parameter, allowing validation errors to be suppressed and an administrator account to be created.
Risk Assessment
An unauthenticated attacker can create an administrator-level account on the WordPress site, leading to full compromise of the website.
Recommendation
Immediately update the Advanced Custom Fields: Extended plugin to the latest available version that fixes this vulnerability.
Other vulnerabilities in Advanced Custom Fields: Extended
See all- CVE-2026-80467High
The Advanced Custom Fields: Extended WordPress plugin before 0.9.2.7 does not restrict the role submitted through its front-end user forms to the roles the form actually offers, and its safeguard against privileged roles is incomplete. This allows unauthenticated visitors to register an account with elevated capabilities and then escalate it to administrator.
- CVE-2026-12526High
The Advanced Custom Fields: Extended WordPress plugin before 0.9.2.7 does not verify that the requester is authorized to edit the targeted user account in the update-user action of its front-end Forms module; it only checks a capability when the submitted role is administrator or super_admin. On a site that exposes a publicly reachable front-end form whose user-update action targets an existing administrator and maps the password to a visitor-submitted field, an unauthenticated visitor can overwrite that administrator's password and take over the account. The default target is the submitting user, so exploitation depends on the form being configured to target another account.
- CVE-2025-15463Medium
The Advanced Custom Fields: Extended plugin for WordPress up to version 0.9.2.3 is vulnerable to arbitrary shortcode execution. This is due to improper validation before running do_shortcode, allowing unauthenticated attackers to execute arbitrary shortcodes.
Original NVD description (English source)
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.
Vulnerability data from NVD (NIST) · CISA KEV · EPSS