CVE-2026-79680

EUVD-2026-85846
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.
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
QtCNA
4.5 MEDIUM
NETWORK
LOW
NONE
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:A/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:U/V:D/RE:L
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
Early Detection
Affected products identified ahead of NVD analysis through intelligence sources.
VendorProductVersionSource
qtqt
6.4.0 ≤
𝑥
< 6.8.9
CNA
qtqt
6.9.0 ≤
𝑥
< 6.11.3
CNA
Common Weakness Enumeration
References
https://codereview.qt-project.org/c/qt/tqtc-qtvncserver/+/759160
https://wiki.qt.io/List_of_known_vulnerabilities_in_Qt_products#CVE-2026-79680: