CVE-2026-13439 json
Easy Form Builder by WhiteStudio <= 4.0.11 - Unauthenticated Privilege Escalation to Administrator via Password Recovery REST Endpoint
published 3mo ago modified 3mo ago also EUVD-2026-46156
- cvss
- 9.8
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.7%
- EPSS 0.7% chance of exploitation in 30 days, percentile 53%
- public exploits
- 0
- none known
Summary
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.
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Check with FencerCISA SSVC
- Exploitation
- none
- Automatable
- yes
- Technical impact
- total
- Assessed
- 3mo ago
Exploit prediction
0.71% chance of exploitation in the next 30 days, higher than 53% of all scored CVEs (FIRST EPSS, 2026-11-09).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
Affected products
- hassantafreshi Easy Form Builder by WhiteStudio – Drag & Drop Form Builder
Classification
- Weakness
-
- CWE-269 Improper Privilege Management
- Technology feeds
References
- wordfence.com /threat-intel/vulnerabilities/id/df8326b6-a443-4f76-a755-49f89af74d7e?source=cve
- plugins.trac.wordpress.org /browser/easy-form-builder/trunk/includes/class-Emsfb-public.php#L5060
- plugins.trac.wordpress.org /browser/easy-form-builder/trunk/includes/class-Emsfb-public.php#L5024
- plugins.trac.wordpress.org /browser/easy-form-builder/trunk/includes/class-Emsfb-public.php#L1587
- plugins.trac.wordpress.org /browser/easy-form-builder/trunk/includes/class-Emsfb-public.php#L96
- plugins.trac.wordpress.org /browser/easy-form-builder/trunk/includes/class-Emsfb-public.php#L623
- plugins.trac.wordpress.org /changeset/3588226/easy-form-builder/trunk/includes/class-Emsfb-public.php
- plugins.trac.wordpress.org /changeset?old_path=%2Feasy-form-builder/tags/4.0.11&new_path=%2Feasy-form-builder/tags/4.0.12
Sources
- CVE List CVE-2026-13439
- NVD CVE-2026-13439
Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.