Viscosity version 1.5 for Windows and version 1.5.1 for Mac are now available! Version 1.5 brings performance and security improvements to the Windows version, as well as an enhanced Details window under modern Windows operating systems.

The 1.5.1 update for the Mac version of Viscosity brings a number of small fixes and improvements based off feedback from the community. Please don't hesitate to post on our support forum if you encounter any issues or would like to offer feedback!

Version 1.5 Windows Release Notes:

Version 1.5.1 Mac Release Notes:

These updates can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.5 for Mac is now available! This is our biggest update yet, with massive performance and security improvements! This version also brings full 64-bit support, greater support for the latest Mac OS 10.10 (Yosemite) beta and preview versions, and a snazzy new default menu icon with dark mode support.

Please note that version 1.5 ends support for Mac OS 10.5 and 10.6. Viscosity 1.4.10 is still available from the legacy downloads section for these users. In addition, with the move to 64-bit, VPN administrators utilising PKCS#11 should ensure that their driver/provider files are up to date and have 64-bit support.

Version 1.5 Mac Release Notes:

The 1.5 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Hot off the heels of version 1.4.9 comes version 1.4.10. Version 1.4.10 addresses a Man-In-The-Middle (MITM) vulnerability in OpenSSL announced today (CVE-2014-0224). OpenSSL has been updated to version 1.0.1h, which includes a fix for this issue. All users are encouraged to update to this latest version of Viscosity to ensure they remain secure.

For more information regarding the SSL/TLS MITM vulnerability in OpenSSL please refer to the OpenSSL Security Advisory.

Version 1.4.10 Mac Release Notes:

Version 1.4.10 Windows Release Notes:

The 1.4.10 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.9 of Viscosity for both Mac and Windows has just been released! The most notable changes include an update to OpenVPN version 2.3.4, an optional single shared network adapter mode for Windows users, and preliminary Mac OS 10.10 (Yosemite) support for the Mac developers out there with early access.

Version 1.4.9 Mac Release Notes:

Version 1.4.9 Windows Release Notes:

The 1.4.9 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.8 of Viscosity for both Mac and Windows is now available! This version addresses the recent OpenSSL "Heartbleed" security vulnerability, and all users are strongly advised to update to this release as soon as possible.

The OpenSSL "Heartbleed" bug is a very serious vulnerability in versions 1.0.1 to 1.0.1f of OpenSSL. OpenSSL is OpenVPN's default library for providing encryption services and hence OpenVPN users are exposed to this flaw. While it is more difficult for an attacker to target an OpenVPN client than a server, it could still potentially allow an attacker to obtain session keys and decrypted data and so it should be treated seriously. Version 1.0.1g of OpenSSL fixes this flaw and this is the version included with Viscosity 1.4.8.

For more information regarding the OpenSSL "Heartbleed" bug please visit The Heartbleed Bug website. For further information on how this bug can affect OpenVPN users please visit the OpenVPN Community Wiki Page.

Version 1.4.8 Mac Release Notes:

Version 1.4.8 Windows Release Notes:

The 1.4.8 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

We're pleased to announce that version 1.4.7 of Viscosity for both Mac and Windows is now available! We've vastly improved retina display support for Mac users, and high-DPI interface support for Windows users. We've also created some sleek new toolbar icons for Viscosity's Preferences window that make Viscosity look even better on both standard and retina level displays.

Version 1.4.7 Mac Release Notes:

Version 1.4.7 Windows Release Notes:

The 1.4.7 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.6 of Viscosity for Mac is now available! This update includes some small final tweaks in preparation for the release of Mac OS 10.9 (Mavericks). It has been extensively tested under Mavericks to ensure the best possible experience for users updating their Mac. While previous releases of Viscosity will still run under Mavericks, we encourage all users to update to this version.

Version 1.4.6 Mac Release Notes:

The 1.4.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.6 of Viscosity for Windows has just been released! Like the recent Mac update we've greatly improved PKCS#11 support, with it much more straightforward to use for end users. We've also improved two-factor authentication support and made a number of small fixes and enhancements.

Version 1.4.6 Windows Release Notes:

The 1.4.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.5 of Viscosity for Mac is now available! We've greatly improved PKCS#11 support, making it more straightforward to use for end users. We've also vastly improved challenge/response support, making it much easier to implement two-factor authentication in custom OpenVPN environments (check out the forum for some examples).

Version 1.4.5 Mac Release Notes:

The 1.4.5 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Version 1.4.4 of Viscosity for Windows is now available. We've focused on increasing the reliability of connections even further, with lots of small improvements and bug fixes. In addition we've added a number of features for enterprise environments, including improved two-factor authentication support and the ability to set machine wide settings and connection permissions.

Version 1.4.4 Windows Release Notes:

The 1.4.4 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.