CVE-2026-13439 CRITICAL

CVE-2026-13439: Easy Form Builder by WhiteStudio <= 4.0.11 - Unauthenticated Privilege Escalation to Administrator via Password Recovery REST Endpoint

Vendor Hassantafreshi
Product Easy Form Builder by WhiteStudio – Drag & Drop Form Builder
Weakness CWE-269
Published July 21, 2026
Last update July 21, 2026
View on NVD All CVEs

CVSS base score

9.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality High
Integrity High

CVSS vector

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

What the vulnerability does

01Description

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.

Explanation of Vulnerability in Simple Terms

02Summary

Easy Form Builder by WhiteStudio versions up to 4.0.11 contain a privilege management flaw that allows unauthenticated attackers to read, modify, or delete data on the site without any user interaction. The vulnerability affects all versions from 0 to 4.0.11. Site administrators should update immediately to a version newer than 4.0.11.

What an attacker can do

03Attacker Capabilities

Read, modify, or delete any data on the site without authentication.

Potential impact on your site

04Site Impact

Attackers can compromise form data, user information, and site content without logging in.

Conditions required to exploit

05Prerequisites

Network access only; no authentication or user interaction required.

Key dates

06Disclosure timeline

July 21, 2026 CVE published

Related vulnerabilities

08Related CVE

CVE-2026-6897 Wishlist Member <= 3.30.1 - Missing Authorization to Authenticated (Subscriber+) Arbitrary Plugin Options Update via 'wishlistmember_team_accounts_save_settings' AJAX action CVE-2026-9842 Backstage <= 1.4.2 - Unauthenticated Privilege Escalation via Permissive Demo Role Capabilities CVE-2026-1993 ExactMetrics 7.1.0 - 9.0.2 - Authenticated (Custom) Improper Privilege Management to Role Privilege Escalation via Settings Update CVE-2026-6895 Wishlist Member <= 3.30.1 - Missing Authorization to Authenticated (Subscriber+) API Secret Key Disclosure and Privilege Escalation via 'wlm3_export_settings' AJAX Action CVE-2026-8206 Kirki 6.0.0 - 6.0.6 - Unauthenticated Privilege Escalation via 'handle_forgot_password'