Release notes

Synergy 3

Personal licenses now activate once online and then work fully offline, so the app keeps running on restricted or disconnected networks.

Wayland users now keep their input capture permission across configuration changes, so there is no need to grant it again each time (requires the latest Wayland libraries).
A new setting in 'Local settings' lets you choose between the stable update track and the beta track for receiving new releases.

Updated the underlying Core engine to version 1.20.3, the latest available release of the component that powers sharing between computers.
Installations now run natively on Ubuntu 26.04, so users on the newest Ubuntu release are supported out of the box.
Support has been extended to Fedora 43 and Fedora 44.
Renewed the certificate that proves the Windows release is genuine, keeping installations and updates trusted by your system.

Addressed a crash on macOS that made the cursor bounce back when moving between screens at a screen edge.
Eliminated another crash on macOS that could be triggered while the screen saver was starting up.
Resolved an issue where an error saying "failed to get permission status from os" could appear without showing a way to resolve it.
Restored the ability to send Ctrl+Alt+Del to a Windows client when using hotkeys with elevated permission.
Stopped horizontal mouse scrolling from failing on a Windows client, so side-to-side scrolling works as expected again.
Corrected a problem where the security certificate was not regenerated after changing the key length, so the new setting now takes effect.
Reduced how often the background service on Windows produces the unexpected response "ok\nok\n".

Fixed an intermittent error showing "core ipc read timeout after 2000 ms" caused by making many settings changes in rapid succession.
Eliminated a local privilege escalation path that let unauthenticated users gain elevated system access (CVE-2026-41477).
Patched a clipboard memory safety vulnerability that could be exploited to crash the program or run malicious code (CVE-2026-41476).
Corrected a denial of service (DoS) vulnerability where a TLS server and its connected clients became unreachable when a non-TLS client attempted to connect (CVE-2026-44296).
Stopped newer clients from being incorrectly rejected with an incompatibility error when connecting to the server.
Updated bundled dependencies to current versions, including upstream security patches.

Addressed an issue on macOS Tahoe 26 where the background service could remain running after the application was deleted.
Fixed Core restarts during UAC prompts or login when the elevation setting was configured to Always.
Restored compatibility between installations running v3.4 and v3.5, preventing failures caused by database format differences.
Eliminated intermittent Core restarts and reconnect loops reported on macOS Tahoe.
Fixed old background services continuing to run in the background on Windows after an update.
Corrected EADDRINUSE (address already in use) error that prevented the service from starting on Linux.
Resolved startup failures on Intel Macs running macOS 14.6 where the service would not launch.
Resolved connection failures when adding a computer whose database version differed by one revision.
Fixed drag-and-drop error messages appearing in older versions after connecting to a newer installation.
Addressed Wayland compatibility on Arch Linux where GUI wouldn't start.
Retry mechanism for macOS error message “failed to get permission status from os” which appears intermittently.
Updated macOS installer disk image to restore on-screen installation instructions in the background artwork.