OpenVPN and OpenSSL Versions Included in Tunnelblick

Tunnelblick includes multiple versions of OpenVPN to accomodate several types of use. You may choose which version of OpenVPN will be used to connect a configuration on the "Settings" tab of the "Configurations" panel of Tunnelblick's "VPN Details" window.

Typically, Tunnelblick includes:

• OpenVPN 2.4, which is obsolete and included to connect to old VPN servers which do not support higher versions of OpenVPN.
• OpenVPN 2.5, which is used by default in Tunnelblick 3.
• OpenVPN 2.6, which is the most recent version and is used by default in Tunnelblick 4.

Beta versions of Tunnelblick may include unreleased versions of OpenVPN. These versions of OpenVPN should be used only for testing new features of OpenVPN. They have not been as thoroughly tested as released versions of OpenVPN and they may contain serious security vulnerabilities.

OpenSSL Versions

Tunnelblick's copies of OpenVPN include OpenSSL or LibreSSL libraries:

• Openvpn 2.6 includes only the latest long-term-support version of OpenSSL, 3.0, which will be supported until 2026-09-07.
• OpenVPN 2.4 and 2.5 include only OpenSSL, 1.1.1, which is no longer supported as of 2023-09-11.
• OpenVPN 2.3 does not work with OpenSSL 1.1.1, so one of Tunnelblick's copies of OpenVPN 2.3 includes OpenSSL 1.0.2, which is out of support and should not be used. The other copy of OpenVPN 2.3 includes LibreSSL 2.7.1, which is similarly no longer supported.