Easy Form Builder by WhiteStudio <= 4.0.11 - Unauthenticated Privilege Escalation to Administrator via Password Recovery REST Endpoint
Summary
| CVE | CVE-2026-13439 |
|---|---|
| State | PUBLISHED |
| Assigner | Wordfence |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-21 06:16:28 UTC |
| Updated | 2026-07-21 16:54:45 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v3.1 9.8 CRITICAL from [email protected]
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS: 0.004010000 probability, percentile 0.325290000 (date 2026-07-21)
Problem Types: CWE-269 | CWE-269 CWE-269 Improper Privilege Management
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| 3.1 | CNA | DECLARED | 9.8 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Hassantafreshi | Easy Form Builder By WhiteStudio Drag Drop Form Builder | affected 4.0.11 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| plugins.trac.wordpress.org/changeset | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/easy-form-builder/trunk/includes/class-Emsfb-public.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/easy-form-builder/trunk/includes/class-Emsfb-public.php | [email protected] | plugins.trac.wordpress.org | |
| www.wordfence.com/threat-intel/vulnerabilities/id/df8326b6-a443-4f76-a755-49f89... | [email protected] | www.wordfence.com | |
| plugins.trac.wordpress.org/browser/easy-form-builder/trunk/includes/class-Emsfb-public.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/easy-form-builder/trunk/includes/class-Emsfb-public.php | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/changeset/3588226/easy-form-builder/trunk/includes/class-Emsf... | [email protected] | plugins.trac.wordpress.org | |
| plugins.trac.wordpress.org/browser/easy-form-builder/trunk/includes/class-Emsfb-public.php | [email protected] | plugins.trac.wordpress.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: CHOIGYEONGMIN (en)
Additional Advisory Data
| Source | Time | Event |
|---|---|---|
| CNA | 2026-07-20T17:07:28.000Z | Disclosed |
There are currently no legacy QID mappings associated with this CVE.