CVE-2026-75027 in Themify Builder Plugin
Summary
by MITRE • 08/22/2026
The Themify Builder plugin for WordPress is vulnerable to authorization bypass in all versions up to, and including, 7.8.0. This is due to the plugin not properly verifying that a user is authorized to perform an action. This makes it possible for unauthenticated attackers to modify the stored Themify Builder styling data (padding and margin properties) of arbitrary posts, including private and draft posts, by supplying an attacker-controlled post ID and JSON styling payload. The nonce required by the handler is automatically emitted to all frontend pages rendered by the builder via wp_localize_script, meaning any unauthenticated visitor can trivially retrieve a valid nonce from page source and satisfy the only access control in place.
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Analysis
by VulDB Data Team • 08/22/2026
The Themify Builder plugin for WordPress contains a critical authorization bypass vulnerability affecting all versions up to 7.8.0. This flaw stems from an insufficient verification of user privileges when handling requests that modify styling data. Specifically, the application logic fails to enforce proper access controls on endpoints responsible for updating post metadata related to visual design elements such as padding and margin properties. Consequently, any individual with network connectivity to the targeted WordPress instance can exploit this weakness without possessing valid credentials or administrative rights.
The technical mechanism of exploitation relies on the improper handling of nonces, which are cryptographic tokens used in WordPress to prevent Cross-Site Request Forgery attacks. In a secure implementation, these tokens should be generated per-session and strictly validated against the authenticated user's context. However, in this vulnerable version, the nonce required by the styling update handler is emitted globally via the wp_localize_script function on all frontend pages rendered by the builder. This design choice effectively neutralizes the protective value of the nonce because it becomes publicly accessible information rather than a secret tied to an authenticated session. An attacker can simply view the source code of any public page utilizing the Themify Builder, extract the valid nonce, and use it in subsequent malicious requests.
The operational impact of this vulnerability is significant as it allows unauthenticated attackers to arbitrarily modify stored styling data for posts regardless of their visibility status. This includes private posts that are intended to be accessible only to specific users or administrators, as well as draft posts that have not yet been published. By supplying an attacker-controlled post ID along with a JSON payload containing maliciously crafted padding and margin properties, the adversary can alter the visual presentation of content on the website. While this primarily affects the aesthetic rendering rather than executing arbitrary code directly, it undermines data integrity and confidentiality by exposing private content structures and allowing unauthorized manipulation of site appearance.
From a classification perspective, this vulnerability aligns with CWE-284, which describes Improper Access Control, specifically highlighting failures in authorization checks that allow unauthenticated users to perform privileged actions. It also maps to MITRE ATT&CK technique T1078, Valid Accounts, although in this case the attacker does not need valid accounts but rather exploits a flaw that mimics authorized access through leaked authentication tokens. The ability to modify private and draft content further implicates CWE-200, Information Exposure, as it reveals internal post structures and allows manipulation of content intended for restricted audiences.
Mitigation strategies must focus on restricting the scope of nonces and enforcing strict server-side authorization checks. Developers should ensure that nonces are generated per-user session rather than globally emitted to all visitors. Furthermore, every endpoint handling sensitive data modifications must verify not only the presence of a valid nonce but also confirm that the requesting user possesses the necessary capabilities or roles associated with that specific post ID. Updating to a patched version where these access controls are properly implemented is essential for restoring security integrity. Until an update is applied, administrators should consider disabling the Themify Builder plugin if it is not actively required, thereby removing the attack surface entirely from the environment.