Improper privilege management in hwk-fr Advanced Custom Fields: Extended
Key facts
- Attack vector
- Network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Privilege escalation
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- No fix listed
Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-269.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- Yes
- Technical impact
- Total
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2026-8809
- 2026-10-03 Alias added: GHSA-jvvq-c627-79xm
References
Other 6
- https://www.wordfence.com/threat-intel/vulnerabilities/id/bd332f49-5aa9-4207-89db-84692a6430e0?source=cve
- https://plugins.trac.wordpress.org/browser/acf-extended/tags/0.9.2.4/includes/module-acf.php#L141
- https://plugins.trac.wordpress.org/browser/acf-extended/tags/0.9.2.4/includes/hooks.php#L636
- https://plugins.trac.wordpress.org/browser/acf-extended/tags/0.9.2.4/includes/modules/form/module-form-action-user.php#L715
- https://plugins.trac.wordpress.org/browser/acf-extended/tags/0.9.2.4/includes/modules/form/module-form-front.php#L94
- https://plugins.trac.wordpress.org/changeset/3551665/acf-extended
More hwk-fr vulnerabilities
- TI-2025-12329 Advanced Custom Fields: Extended 0.9.0.5 - 0.9.1.1 - Unauthenticated Remote Code Execution in prepare_form CVSS 3.1CRITICAL 9.8
- TI-2025-13276 Advanced Custom Fields: Extended <= 0.9.2.1 - Unauthenticated Privilege Escalation via Insert User Form Action CVSS 3.1CRITICAL 9.8
- TI-2026-83241 Advanced Custom Fields: Extended exposes user password hashes CVSS 3.1HIGH 7.5
- TI-2025-14104 Advanced Custom Fields: Extended <= 0.9.2.3 - Unauthenticated Arbitrary Shortcode Execution CVSS 3.1MEDIUM 6.5
- TI-2024-21446 WordPress WP 404 Auto Redirect to Similar Post plugin <= 1.0.4 - Reflected Cross Site Scripting (XSS) vulnerability CVSS 3.1HIGH 7.1
- TI-2026-81718 Missing authorization in Advanced Custom Fields: Extended CVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-8809 · CVE Program
- CVE-2026-8809 · NVD
- FIRST EPSS
- GHSA-jvvq-c627-79xm · GitHub Advisory Database · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences