Viscosity version 1.10.8 is now available for macOS! This update is a maintenance release with internal improvements, bug fixes, and minor enhancements to keep Viscosity running smoothly.

This is the final release to ship with OpenVPN 2.5 and the 1.1.1 branch of OpenSSL. Future versions of Viscosity will be moving to OpenVPN 2.6 and OpenSSL 3.0. We will have more information about these upcoming changes in a future post.

Version 1.10.8 Mac Release Notes:

The 1.10.8 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.6 is now available for Windows! This update includes significant changes to fully natively support ARM64 machines, updates to modernize framework and API usage on Windows, an updated version of OpenSSL, and many bug fixes and enhancements.

In particular, this update now completes Viscosity's ARM64 support. Viscosity first introduced support for Windows on ARM64 (WoA) in version 1.8.2, with all of Viscosity's core components (including OpenVPN connections) ported to run natively. However there was one component that we couldn't port at the time: Viscosity's user interface. Viscosity's user interface relies on the Windows WinForms and WPF frameworks, which didn't have native ARM64 support at the time. However with ARM64 support introduced for these in .NET 4.8.1, we're pleased to announce that Viscosity's user interface is now running natively on ARM64 as well.

This update also resolves several display and rendering issues on the most recent versions of Windows 11, including an issue that could cause Viscosity's toolbar to render in the wrong system color or not respect dark mode. Web authentication (SSO and SAML) support has also been improved, with a number of small issues resolved that could cause an authentication request to fail or a session token to be rejected.

To better support modern versions of Windows (as well as for ARM64 support), Viscosity now requires .NET 4.8.1 and the Visual C++ 2022 runtime. Viscosity's installer will automatically handle upgrading these if required.

Finally, Windows 10 version 2004 (also known as 20H1 and Build 19041) and earlier are no longer supported. Viscosity now requires Windows 10 version 20H2 (Build 19042) or later. With Microsoft no longer issuing security updates for these older versions, we encourage any existing users of these versions to update their copy of Windows.

Version 1.10.6 Windows Release Notes:

The 1.10.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.7 is now available for macOS! This update is a small maintenance release with bug fixes and minor enhancements to keep Viscosity running smoothly.

In particular, this version fixes a number of DNS related issues that could cause domains to fail to resolve with certain upstream DNS servers, as well as an issue that could cause DNS settings to remain after a VPN connection is disconnected (typically resulting in DNS lookups to fail).

This update also resolves some issues that could cause reachability checks to fail shortly after connecting or when a macOS routing change occurs, resulting in the associated VPN connection being disconnected.

Version 1.10.7 Mac Release Notes:

The 1.10.7 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.6 is now available for macOS! This update includes significant enhancements to DNS functionality, IPv6 support improvements, updates to better support the upcoming macOS 14 (Sonoma) release, an updated version of OpenSSL, and many bug fixes and enhancements.

In particular, this update overhauls Viscosity's DNS engine, allowing Viscosity to support DNS servers and domains set via IPv6 router advertisements (RDNSS and DNSSL), better support for DNS resolution in mixed-IP environments, smarter server fallback selection when one or more DNS servers are unavailable, and general reliability improvements for macOS 13.

IPv6 support has also been improved for bridged (TAP) VPN connections. For those that desire full IPv6 auto-configuration of the VPN connection, Viscosity now supports a new "route-ipv6-gateway auto" flag that allows the IPv6 gateway provided by a router advertisement to be used as the default VPN gateway. This can be added as an advanced command in Viscosity.

This update also improves web authentication (SSO and SAML), and resolves a number of small issues that could cause an authentication request to mistakenly fail. In particular, this update should resolve occasional authentication issues when using Azure Active Directory as the SAML backend.

This will be the last release to support macOS 10.15. Future updates will require macOS 11 or later. With Apple no longer issuing security updates for macOS 10.15, we encourage any existing 10.15 users to update to macOS 11 or later.

For the Windows users, the Windows version of Viscosity 1.10.6 will be available later this month (with some exciting ARM64 improvements!).

Version 1.10.6 Mac Release Notes:

The 1.10.6 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.5 has been released for both macOS and Windows! This version includes several requested features and improvements, including scripting enhancements, connection import compatibility, OpenVPN and OpenSSL updates, and many small bug fixes and enhancements.

In particular, the ability of a Before-Connect script to return a challenge response has been highly requested. This allows for easier integration with software for generating one-time codes and passwords (for example, generating a TOTP code using 1Password) as well as integration with web and application APIs for generating codes or approving connections. Documentation for how to return a challenge from a script can be found in the Knowledge Base.

On macOS the two-factor challenge window now also supports auto-filling. This allows for one-time items like SMS codes to be automatically entered instead of manually typed in or copy-pasted from Messages.

Although a minor change, we received a *lot* of feedback asking for Viscosity's Preference window to be renamed Settings on macOS 13 to match the new "System Settings" naming. So we've gone ahead and made the change! Now when running on macOS 13 or later, Viscosity's Preference window will be named Settings (it will remain as Preferences on macOS 12 and earlier). We've also taken the opportunity to update the naming on Windows to be Settings as well, to better match Windows 10 and 11 schemes.

This version also updates OpenVPN to version 2.5.9, and OpenSSL to version 1.1.1t. The OpenSSL update includes some low-severity security fixes that could potentially impact VPN client connections, so we recommend all users update.

During installation on Windows, the installer will now display a warning if attempting to install Viscosity to a custom non-standard location with unsafe permissions. If Viscosity is installed to a custom location with inappropriate permissions, an attacker with local access could potentially modify the installation and gain elevated privileges. This warning should prevent those unfamiliar with Windows file permissions from accidentally making this mistake. Special thanks to Will Dormann for reporting this to us.

Finally, this release removes OpenVPN 2.4, which is now considered end-of-life. OpenVPN 2.5 has been the default version used in Viscosity for many years and is backwards compatible with servers running older versions (so this change won't prevent connecting to servers running OpenVPN 2.4 or older versions). However, in some rare instances, you may need to make small changes to your VPN connection's configuration in Viscosity for it to be supported by version 2.5. If you need help updating your connection's settings, please don't hesitate to reach out to us.

Version 1.10.5 Mac Release Notes:

Version 1.10.5 Windows Release Notes:

The 1.10.5 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.4 is now available for both macOS and Windows! This update adds several highly requested features and improvements, including macOS Keychain identity and token support, performance improvements, update alert changes, and improved support for both macOS 13 (Ventura) and Windows Server 2022. An update to OpenSSL is also included, along with many bug fixes and enhancements.

In particular, we're please to announce that this version includes support for identities (a certificate and private-key combination) stored in the macOS Keychain or on tokens with macOS support. This should be of particular benefit to enterprise deployments that include PKI identities as part of their deployment. Using identities stored on tokens is also now a much easier process: no more having to install and configure PKCS#11 drivers to use tokens and smartcards for authentication! We'll be posting more information on how to make the best use of this new feature, however it can be found under the new "System Identity" authentication option when editing a VPN connection in Viscosity.

This update also improves support for macOS 13 (Ventura) and adopts several new macOS frameworks for improved compatibility and performance. All macOS 13 users are encouraged to update. We've also placed a focus on improving cryptographic performance with this update, managing some modest performance improvements to VPN connections on both Intel and Apple Silicon Macs.

On the Windows side, the Viscosity Virtual Adapter has been updated to support Windows Server 2022. Users upgrading their Windows install will also benefit, as the driver will now also be automatically updated when updating Windows from version 10 to 11 without the need to uninstall/reinstall Viscosity.

Looking towards the future, this update will be the last version of Viscosity to include OpenVPN 2.4. OpenVPN 2.5 has been the default version used for many years now, and version 2.4 will soon reach end-of-life. Please note that you'll still be able to connect to OpenVPN servers running version 2.4 (or even older versions). However in some rare instances you may need to make small changes to your configuration in Viscosity so it is supported by version 2.5.

Finally, this version also updates OpenSSL to version 1.1.1s.

Version 1.10.4 Mac Release Notes:

Version 1.10.4 Windows Release Notes:

The 1.10.4 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.3 has been released for both macOS and Windows! This version adds several commonly requested features, including VPN connection sorting, and separately prompting for two-factor credentials that normally form part of the password. Updates to OpenVPN and OpenSSL are also included, along with many small bug fixes and enhancements.

This update adds a new static-challenge-password command to allow Viscosity to separately prompt for a two-factor credential (such as a one-time password or PIN) and append this credential to the password sent to the server. While we encourage VPN administrators to adopt OpenVPN's static/dynamic challenge support instead (such as documented in the Two-Factor Authentication Setup Guides), we understand there are many legacy setups out there still using this approach. This will allow for a much smoother experience, including enabling username and passwords to be saved without affecting the two-factor prompt.

Another common feature request we've added is the ability to quickly sort VPN connections and folders to make organising and managing them faster. Several sorting options are available, including sorting all connections and folders, just selected items, or just items in a folder. Simply right-click (or control-click) on the items to be sorted and select the appropriate Sort menu option.

On the Windows side, Viscosity will now automatically detect and repair certain issues with a VPN connection's virtual network interface that could cause a connection attempt to fail. When this occurred, Viscosity would disconnect the connection shortly after starting, with an error message in the log indicating the network adapter could not be found. We discovered that in some instances severely out-of-date third-party network filters attached to the VPN interface could cause it to fail. Viscosity will now detect when this is the case and repair the problem.

On macOS, an issue with the Viscosity helper has been resolved that could on rare occasions cause the helper to crash when sleeping the computer with an active VPN connection. This largely only occurred for Apple Silicon users with TAP connections, however in very rare instances it could also occur on Intel Macs, requiring Viscosity to be re-launched on wake.

Finally, this version also updates OpenVPN 2.5 to version 2.5.7, OpenVPN 2.4 to version 2.4.12, and OpenSSL to version 1.1.1o. These updates include a number of small bug fixes and improvements.

Version 1.10.3 Mac Release Notes:

Version 1.10.3 Windows Release Notes:

The 1.10.3 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.2 is now available for both macOS and Windows! This update introduces Dark Mode support for the Windows version, a security-related OpenSSL update for both macOS and Windows versions, along with several small bug fixes and enhancements.

The updated version of OpenSSL addresses a potential security issue with OpenSSL's certificate parsing that could result in a denial-of-service attack. This does not affect the security of OpenVPN connections. However, it could potentially allow a malicious server or man-in-the-middle attacker to stall a VPN connection attempt with an infinite loop, resulting in high CPU usage until the connection attempt is disconnected.

The Windows version also introduces preliminary Dark Mode support. If Windows is set to use Dark Mode, Viscosity will now automatically render its interface using the appropriate dark theme colors. This is still a work in progress, however Dark Mode fans should be less blinded when opening Viscosity's interface with this update.

The macOS version also fixes a number of small IPv6 related issues, including not correctly displaying the IPv6 address assigned to a VPN connection in the menu or Details window.

Version 1.10.2 Mac Release Notes:

Version 1.10.2 Windows Release Notes:

The 1.10.2 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity version 1.10.1 is now available for both macOS and Windows! This update is primarily a small maintenance release with bug fixes and minor enhancements to keep Viscosity running smoothly.

In particular, the Mac version is now able to detect and workaround an issue that caused Viscosity to hang in the background when trying to update old versions of its helper tool on macOS 12. It is no longer necessary to manually remove old versions of the helper on macOS 12 in these instances.

The Windows version also resolves a similar issue that could cause VPN connections to fail if Windows had been upgraded from Windows 10 to Windows 11 without the driver being manually updated.

Version 1.10.1 Mac Release Notes:

Version 1.10.1 Windows Release Notes:

The 1.10.1 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.

Viscosity 1.10 is now available for both macOS and Windows! This is a big update, with OpenVPN 2.5 support, support for both macOS 12 and Windows 11, support for SSO and SAML authentication, and lots of other new features and improvements.

OpenVPN 2.5 brings several new features to VPN connections, including support for the ChaCha20-Poly1305 cipher, TLS 1.3 support, improved session token management, and many other networking improvements. OpenVPN 2.5 is backwards compatible with servers running older versions of OpenVPN, however Viscosity still includes OpenVPN 2.4 which can be enabled at any time under Preferences->Advanced.

This release also adds support for the latest macOS and Windows operating systems. macOS 12 (Monterey), expected to be available shortly, is now supported. Windows 11, just recently released, is now fully supported as well.

Please note that while macOS 12 is supported, iCloud Private Relay beta (available in macOS 12) has several known incompatibilities with common VPN setups. We hope to have improved compatibility with Private Relay in a future update.

Viscosity 1.10 also introduces support for SSO and SAML authentication, allowing OpenVPN setups to better integrate into existing enterprise authentication systems. For those with custom OpenVPN server setups, we expect to have setup guides on how to configure SSO/SAML server-side in our knowledge base soon.

Viscosity’s Import from Server feature has also been overhauled, and now supports a number of new features, including web-based authentication (including SSO/SAML), automatic detection and TOTP two-factor enrollment, and support for OpenVPN Cloud.

Also included are many additional small improvements and bug fixes. More details can be found in the release notes below.

Finally, this update requires macOS 10.15 or later on Mac, and Windows 10 or later on Windows. macOS 10.13 and 10.14, and Windows 7 and 8.1, are no longer supported. These older OS versions are either no longer receiving security updates, or require the use of deprecated OS APIs that make supporting newer OS versions significantly more difficult. Older Viscosity releases that will run on these versions can still be found at the Legacy Downloads page.

Version 1.10 Mac Release Notes:

Version 1.10 Windows Release Notes:

The 1.10 update can be automatically installed from inside Viscosity, or downloaded and manually installed. For support with this version please visit our support section.