Skip to main content
CVE-2026-123139VulnerabilityPublished

Improper verification of the source of a communication channel vulnerability in Opera Neon on macOS and Windows allows

Source GCVE Database

0
Compare
Authoritative record:CVE-2026-123139· Medium 5.8

Not known to be exploited · CVSS 5.8 Medium.

Data as of 12 Nov 2026, 16:48 UTC

CVSS 4.0 base score
5.8Medium
How severe the flaw is on the 0–10 CVSS scale.

Thin evidence

One scorer or none
CVSS scores by source
CNA (Opera)CVSS 4.05.8
CVSS: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:U

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 12 Nov 2026

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq Mirage: no evidence on record.

    No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.

What to do

Affected software

ProductAffectedFixed in
OperaNeonAffected
  • =1.0.0
Fixed in–

Description

A vulnerability in Opera Neon on macOS and Windows allows a malicious browser extension to take control of the browser by exploiting improper verification of the source of a communication channel. This affects the Opera Neon MCP Hub extension version 0.0.1. The flaw enables commands to be sent through MCP Hub to the built-in Browser Operator extension without proper source validation.

References

Community reviews

Loading reviews…