All vulnerabilities
CVE-2026-79680

qt: Authentication bypass vulnerability in the password authentication mechanism of the Qt VNC Server module

qt qt
Open in ThreatlineRecord JSON
CVSS
4.5Medium
ExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.34%Chance of exploitation activity in the next 30 days, higher than 26% of CVEs. Scored 23 Oct 2026FIRST EPSS
Fixed in6.8.9Also 6.11.3CVE List
Published24 Sep 2026Updated 24 Sep 2026CVE List

What fixes it

A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.

Description

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.

Text from CVE List

Affected versions 2

  • qtaffected: 6.4.0 before 6.8.9CVE List
  • qtaffected: 6.9.0 before 6.11.3CVE List

References 2