WhiteStudio Easy Form Builder Plugin up to 4.0.11 on WordPress Password Recovery efb_set_password sid password recovery

Summaryinfo

A vulnerability was found in WhiteStudio Easy Form Builder Plugin up to 4.0.11. It has been rated as critical. This impacts the function efb_set_password of the file /v1/forms/recovery/efb_set_password of the component Password Recovery. The manipulation of the argument sid leads to password recovery. This vulnerability is uniquely identified as CVE-2026-13439. The attack is possible to be carried out remotely. No exploit exists.

Detailsinfo

A vulnerability was found in WhiteStudio Easy Form Builder Plugin up to 4.0.11. It has been rated as critical. This issue affects the function efb_set_password of the file /v1/forms/recovery/efb_set_password of the component Password Recovery. The manipulation of the argument sid with an unknown input leads to a password recovery vulnerability. Using CWE to declare the problem leads to CWE-640. The product contains a mechanism for users to recover or change their passwords without knowing the original password, but the mechanism is weak. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at wordfence.com. The identification of this vulnerability is CVE-2026-13439 since 06/26/2026. The exploitation is known to be easy. The attack may be initiated remotely. No form of authentication is needed for a successful exploitation. Technical details of the vulnerability are known, but there is no available exploit. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/21/2026). The attack technique deployed by this issue is T1552 according to MITRE ATT&CK.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-46156). Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

• WordPress Plugin

Vendor

• WhiteStudio

Name

• Easy Form Builder Plugin

Version

• 4.0.0
• 4.0.1
• 4.0.2
• 4.0.3
• 4.0.4
• 4.0.5
• 4.0.6
• 4.0.7
• 4.0.8
• 4.0.9
• 4.0.10
• 4.0.11

CPE 2.3info

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CPE 2.2info

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Be aware that VulDB is the high quality source for vulnerability data.

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