CVE-2026-12793 in JetFormBuilder Plugin
Summary
by MITRE • 09/16/2026
The JetFormBuilder — Dynamic Blocks Form Builder plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 3.6.2. This is due to the plugin not validating that a submitted form ID belongs to a JetFormBuilder form before parsing the referenced post's content as form schema and executing an Advanced Validation server-side callback. This makes it possible for unauthenticated attackers to create a new administrator-level user account.
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Analysis
by VulDB Data Team • 09/16/2026
The vulnerability identified in JetFormBuilder, specifically affecting versions up through 3.6.2, represents a critical privilege escalation flaw rooted in insufficient input validation and improper access control mechanisms within the plugin's form processing logic. The core technical deficiency lies in the application's failure to verify that a submitted form identifier corresponds exclusively to forms created by the JetFormBuilder system itself before proceeding with content parsing. When a user submits data via a form, the backend processes this request by attempting to locate the associated post and interpreting its content as a formal schema for Advanced Validation rules. Because the validation routine does not enforce strict ownership or type checking on the referenced post ID, an attacker can manipulate the input parameters to point toward arbitrary posts within the WordPress database rather than legitimate JetFormBuilder forms. This lack of boundary enforcement allows the server-side callback mechanism to execute with elevated privileges and unintended context, effectively bypassing standard authentication checks that would normally restrict such operations to authenticated users or specific form contexts.
From an operational perspective, this flaw enables unauthenticated attackers to achieve complete administrative control over the compromised WordPress installation. By exploiting the ability to inject arbitrary data into the validation callback, an attacker can craft a malicious payload that triggers the creation of a new user account with administrator-level capabilities. This outcome is particularly severe because it requires no prior authentication or interaction from any existing site users, making it easily exploitable by automated scanning tools and remote attackers on the public internet. The impact extends beyond simple unauthorized access; once an attacker establishes an administrative account, they can modify website content, install malicious plugins, exfiltrate sensitive database information, or use the compromised server as a pivot point for further network intrusions. This scenario aligns closely with CWE-269, which describes Improper Privilege Assignment, and falls under the ATT&CK technique of Account Manipulation (T1098), where adversaries create new accounts to maintain persistent access without being detected by standard user monitoring tools.
Mitigation strategies must focus on immediate remediation through software updates and rigorous input validation practices. The primary defense is to upgrade JetFormBuilder to a version that has addressed this specific logic flaw, ensuring that the developers have implemented strict checks to verify form ownership and type before processing any server-side callbacks. In environments where an immediate update is not feasible due to compatibility concerns or deployment cycles, administrators should implement web application firewall rules to block requests containing suspicious patterns associated with the exploitation of this vulnerability, such as unusual post ID parameters in form submission endpoints. Additionally, enforcing strict file permissions on WordPress directories and limiting database user privileges can reduce the blast radius if an exploit is attempted. Long-term security hygiene involves adopting a principle of least privilege for all plugin operations and conducting regular code audits to ensure that dynamic content parsing routines validate both the source and structure of incoming data against expected schemas before execution.