CVE-2002-1336: Tightvnc

High severity, CVSS 7.5. EPSS: 2.4% chance of exploitation in the next 30 days.

TightVNC before 1.2.6 generates the same challenge string for multiple connections, which allows remote attackers to bypass VNC authentication by sniffing the challenge and response of other users.

Affected products

• Tightvnc Tightvnc: version 1.2.0 only; version 1.2.1 only; version 1.2.3 only; version 1.2.4 only; version 1.2.5 only

Published 2002-12-11. Last modified 2026-06-16.