CVE-2026-111958

Royal MCP – Secure AI Connector for Claude, ChatGPT & any LLM via MCP < 1.5.7 - Authentication Bypass

2026-10-20 00:00

Strategic Overview

Status: Patched in 1.5.7
Affected Plugin: Royal MCP – Secure AI Connector for Claude, ChatGPT & any LLM via MCP
Affected Version: < 1.5.7
CVSS: 7.5High
Weakness type: CWE-287 · Improper Authentication
CVE: CVE-2026-111958

View all Royal MCP – Secure AI Connector for Claude, ChatGPT & any LLM via MCP vulnerabilities

At a glance

CVE-2026-111958 is a high-severity Improper Authentication vulnerability in the Royal MCP WordPress plugin, affecting versions < 1.5.7. It carries a CVSS score of 7.5 (reachable over the network; high confidentiality, integrity, availability impact). The issue is fixed in version 1.5.7; sites on affected versions should update now. Disclosed October 2026, reported by Raphael P. Cigana.

Vulnerability Overview

The Royal MCP – Secure AI Connector for Claude, ChatGPT & any LLM via MCP plugin for WordPress is vulnerable to Authentication Bypass in all versions up to 1.5.7 (exclusive). This makes it possible for authenticated attackers, with access to a valid token, to bypass authentication and access the full REST API.

Technical Analysis

The vector marks this flaw as remotely reachable over the network, and no interaction from a victim user. A successful exploit has high impact on confidentiality, integrity, availability — full site compromise territory.

CWE-287: Improper Authentication

Reaching this weakness in Royal MCP < 1.5.7 takes a caller who can reach the endpoint. Improper authentication means the mechanism that proves who a caller is can be satisfied without the secret it was supposed to require.

An attacker authenticates as another user — administrators included — without ever knowing a password, so password policies and login rate limits never come into play. For Royal MCP the fix is 1.5.7: builds < 1.5.7 are affected, anything from 1.5.7 onward is not.

Remediation

Update to version 1.5.7, or a newer patched version

How does WordSec protect against this?

Because it turns on account access, WordSec's login security is the relevant layer: role-based two-factor, captcha and brute-force limits raise the cost of getting the account this needs. None of that substitutes for the fix: Royal MCP 1.5.7 closes this, and updating the plugin is the step that ends it.

Login Security
Alerts

External References

https://www.cve.org/CVERecord?id=CVE-2026-111958 https://www.wordfence.com/threat-intel/vulnerabilities/id/d9d2b2ce-c1a9-48b2-b68f-048cb991e31e https://nvd.nist.gov/vuln/detail/CVE-2026-111958

Related records

Other vulnerabilities in Royal MCP – Secure AI Connector for Claude, ChatGPT & any LLM via MCP

CVSS Vector

7.5

CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Base

Attack VectorNetwork
Attack ComplexityHigh
Privileges RequiredLow
User InteractionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh

This record contains material that is subject to copyright

CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE®). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy.

https://www.cve.org/Legal/TermsOfUse

Defiant hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute this software vulnerability information. Any copy of the software vulnerability information you make for such purposes is authorized provided that you include a hyperlink to this vulnerability record and reproduce Defiant's copyright designation and this license in any such copy.

https://www.wordfence.com/wordfence-intelligence-terms-and-conditions/