Easy Form Builder by WhiteStudio <= 4.0.11 - Unauthenticated Privilege Escalation to Administrator via Password Recovery REST Endpoint
Strategic Overview
- Status
- Patched in 4.0.12
- Affected Plugin
- Easy Form Builder by WhiteStudio – Drag & Drop Form Builder
- Affected Version
<= 4.0.11- CVSS
- 9.8Critical
- Weakness type
- CWE-269 · Improper Privilege Management
- CVE
CVE-2026-13439
At a glance
CVE-2026-13439 is a critical-severity Improper Privilege Management vulnerability in the Easy Form Builder by WhiteStudio WordPress plugin, affecting versions <= 4.0.11. It carries a CVSS score of 9.8 (reachable over the network; low attack complexity; high confidentiality, integrity, availability impact). Exploitation requires no authentication. The issue is fixed in version 4.0.12; sites on affected versions should update now. Disclosed July 2026, reported by CHOIGYEONGMIN.
Vulnerability Overview
The Easy Form Builder by WhiteStudio plugin for WordPress is vulnerable to Unauthenticated Privilege Escalation to Administrator in versions up to, and including, 4.0.11 This is due to the password recovery flow using the publicly-visible session identifier ('sid') as the password reset token stored in wp_emsfb_temp_links, combined with a publicly-accessible nonce refresh endpoint (Emsfb/v1/nonce/refresh) that issues valid WordPress REST nonces to unauthenticated visitors. This makes it possible for unauthenticated attackers to reset the password of any WordPress user — including administrators — by scraping the public sid from a published login form page, submitting a recovery request for any known user email via Emsfb/v1/forms/message/add, and then calling Emsfb/v1/forms/recovery/efb_set_password with the known sid to set an arbitrary new password and gain full administrator access.
Technical Analysis
The vector marks this flaw as remotely reachable over the network, with low attack complexity — no special timing or configuration is needed, and no privileges on the target site, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.
CWE-269: Improper Privilege Management
Easy Form Builder by WhiteStudio <= 4.0.11 carries this weakness at sid, and reaching it takes no account at all. Improper privilege management means the code lets an account end up with capabilities its role should not have.
It converts a low-privileged account into an administrative one, which makes every other restriction on the site irrelevant. For Easy Form Builder by WhiteStudio the fix is 4.0.12: builds <= 4.0.11 are affected, anything from 4.0.12 onward is not.
Remediation
Update to version 4.0.12, or a newer patched version
How does WordSec protect against this?
This one needs no account at all, which puts it outside what login hardening can reach; WordSec's login security narrows the account-level paths around it, and the firewall is what inspects the request itself. None of that substitutes for the fix: Easy Form Builder by WhiteStudio 4.0.12 closes this, and updating the plugin is the step that ends it.
- Login Security
- Alerts
External References
Related records
Other vulnerabilities in Easy Form Builder by WhiteStudio – Drag & Drop Form Builder
- 9.9CVE-2024-30535: Easy Form Builder <= 3.7.4 SQL Injection
CVE-2024-30535 - 7.5CVE-2026-42747: Easy Form Builder by WhiteStudio SQL Injection
CVE-2026-42747 - 7.5CVE-2025-54678: Easy Form Builder <= 3.8.15 SQL Injection
CVE-2025-54678 - 7.2CVE-2026-59517: Easy Form Builder by WhiteStudio Stored XSS
CVE-2026-59517 - 6.4CVE-2024-12112: Easy Form… Authenticated (Subscriber+) Stored XSS
CVE-2024-12112 - 5.5CVE-2022-3906: Easy Form Builder <= 3.3.8 Stored Cross-Site Scripting
CVE-2022-3906 - 5.3CVE-2025-14067: Easy Form Builder Authenticated (Subscriber+)
CVE-2025-14067 - 5.3CVE-2025-67577: Easy Form Builder <= 3.8.20 Missing Authorization
CVE-2025-67577
Vulnerability data © Defiant, Inc., provided under the Wordfence Intelligence T&C