tigroumeow AI Engine Plugin up to 3.8.6 on WordPress MCP module register __return_true improper authorization

Summaryinfo

A vulnerability, which was classified as problematic, was found in tigroumeow AI Engine Plugin up to 3.8.6. The affected element is the function __return_true of the file /wp-json/mcp/v1/oauth/register of the component MCP module. Executing a manipulation can lead to improper authorization. This vulnerability is tracked as CVE-2026-110732. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability has been found in tigroumeow AI Engine Plugin up to 3.8.6 and classified as problematic. This vulnerability affects the function __return_true of the file /wp-json/mcp/v1/oauth/register of the component MCP module. The manipulation with an unknown input leads to a improper authorization vulnerability. The CWE definition for the vulnerability is CWE-285. The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

The AI Engine – The Chatbot, AI Framework & MCP for WordPress plugin for WordPress is vulnerable to Missing Authorization in all versions up to, and including, 3.8.6 This is due to the MCP module's OAuth 2.1 Dynamic Client Registration endpoint (/wp-json/mcp/v1/oauth/register) being registered with a permission_callback of __return_true, allowing an unauthenticated user to register an active OAuth client with an attacker-controlled redirect URI. This makes it possible for unauthenticated attackers to obtain an administrator-bound MCP access token, and thereby full administrator-level control through the MCP tools (including user creation and option updates), once an administrator approves the attacker's client on the OAuth consent screen. The consent page is additionally served without X-Frame-Options or Content-Security-Policy frame-ancestors, so that approval can be obtained via clickjacking.

The advisory is available at wordfence.com. This vulnerability was named CVE-2026-110732 since 10/14/2026. The exploitation appears to be easy. The attack can be initiated remotely. Additional levels of successful authentication are required for exploitation. Successful exploitation requires user interaction by the victim. Technical details are known, but there is no available exploit. The structure of the vulnerability defines a possible price range of USD $0-$5k at the moment (estimation calculated on 10/30/2026). This vulnerability is assigned to T1548.002 by the MITRE ATT&CK project.

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

If you want to get best quality of vulnerability data, you may have to visit VulDB.

Productinfo

Type

• WordPress Plugin

Vendor

• tigroumeow

Name

• AI Engine Plugin

Version

• 3.8.0
• 3.8.1
• 3.8.2
• 3.8.3
• 3.8.4
• 3.8.5
• 3.8.6

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CPE 2.2info

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Entryinfo

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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