CVE-2026-123139: Medium severity vulnerability
Improper verification of the source of a communication channel vulnerability in Opera Neon on macOS and Windows allows a malicious browser extension to take control of the browser by sending commands through MCP Hub to the built-in Browser Operator extension. This issue affects Opera Neon MCP Hub extension: 0.0.1.
Event History
Frequently Asked Questions
Who is exposed to this issue?
Users of Opera Neon on macOS or Windows are exposed if the Opera Neon MCP Hub extension version 0.0.1 is present and a malicious browser extension can send commands through MCP Hub to the built-in Browser Operator extension.
What does an attacker need to exploit it?
The attacker needs a malicious browser extension capable of sending commands through MCP Hub. The vector is local and requires user interaction, while no privileges are required.
What is the potential impact of successful exploitation?
A malicious extension can take control of the browser through commands delivered to the built-in Browser Operator extension. The reported impacts include high confidentiality and integrity impact, with no availability impact.