Summary
CVE-2026-75860 is a critical unauthenticated arbitrary options update vulnerability in the JSON Options WordPress plugin, affecting all versions through 0.0.4. The plugin exposes an action that lacks both capability checks and nonce verification, allowing unauthenticated attackers to modify arbitrary WordPress site options. By manipulating options such as those controlling user registration and default roles, an attacker can enable self-registration with administrator privileges, leading to complete site takeover. The flaw carries a CVSS v3.1 base score of 9.8 (Critical).
Technical details
- Root cause: The plugin registers an action/endpoint that updates arbitrary WordPress options without verifying the requesting user’s capabilities (no
current_user_can()-style check) and without validating a nonce to confirm the request originated from a legitimate, authenticated context (CWE-269: Improper Privilege Management). - Trigger conditions: The vulnerable action is reachable by any unauthenticated visitor sending a crafted request to the affected WordPress site; no login or prior interaction is required.
- Attack vector: Network-based — the request can be sent directly over HTTP(S) to the vulnerable WordPress installation.
- Impact: An attacker can rewrite arbitrary site options, including those that govern user registration and default new-user roles. This can be leveraged to open self-registration and assign the administrator role to a newly created account, resulting in full compromise of the WordPress site (confidentiality, integrity, and availability impact all rated High).
Affected software
- JSON Options WordPress plugin — all versions up to and including 0.0.4
Severity
- CVSS v3.1 Base Score: 9.8 (Critical)
- Vector:
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Mitigation and recommended actions
- Immediate: As of the latest available information, no patched version of the JSON Options plugin has been identified. Security teams should treat any WordPress site running this plugin (version 0.0.4 or earlier) as immediately at risk.
- If no patch is available:
- Deactivate and remove the JSON Options plugin until a fixed release is published by the developer.
- Audit WordPress site options (especially
users_can_registeranddefault_role) and existing administrator accounts for unauthorized changes or unfamiliar users. - Restrict or monitor access to the plugin’s endpoints/actions at the web server or WAF layer as a compensating control.
- Enable logging/alerting on new administrator account creation and changes to registration settings.
- Continuously monitor vendor and plugin repository channels for a security update, and apply it immediately once released.

