CVSS 4.0
5.8 mediumCVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:H/VI:H/VA:N/SC:L/SI:L/SA:N/E:UCVE-2026-123139
Medium (5.8) in opera neon.
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.
Severity
- CWE
- CWE-940 Improper Verification of Source of a Communication Channel
- OWASP Top 10
- A07:2025 Authentication Failures
- Published
- Assigned by
- Opera (CNA)
- NVD analysis
- Not in the NVD yet
- Record from
- the CVE List, synced
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Affected
Versions
From the CNA's record in the CVE List.
| Product | Affected |
|---|---|
| Opera Neon | 1.0.0 |
Attack patterns (CAPEC)
- CAPEC-500 WebView Injection
- CAPEC-594 Traffic Injection
- CAPEC-595 Connection Reset
- CAPEC-596 TCP RST Injection
The attack patterns MITRE's CAPEC relates to this record's weaknesses, as MITRE names them. Credits.