CVE-2026-79680: Qt

Medium severity, CVSS 4.5. EPSS: 0.3% chance of exploitation in the next 30 days.

Authentication bypass vulnerability in the password authentication mechanism of the Qt VNC Server module. An attacker using a specially modified VNC client that violates the RFB protocol can bypass Qt VNC Server's password authentication and gain unauthorized remote access to the shared application, compromising the confidentiality and integrity of the session.

Affected products

• Qt Qt: from 6.4.0, before 6.8.9 (fixed in 6.8.9); from 6.9.0, before 6.11.3 (fixed in 6.11.3)

Published 2026-09-24. Last modified 2026-09-24.