Microsoft released an optional preview update (KB5083631) that fixes a bug causing Remote Desktop (.rdp) security warning dialogs to render incorrectly on multi-monitor systems with mixed display scaling after the April 2026 updates across supported Windows versions. The April security changes introduce one-time and connection-time RDP warnings to block risky resource redirections and counter RDP abuse in phishing campaigns by actors such as APT29. #APT29 #Windows11
Keypoints
- An optional preview update (KB5083631) fixes the RDP security warning rendering issue introduced by the April 2026 updates.
- The bug affected multi-monitor setups with different scaling, causing misaligned buttons and unreadable dialog text that could prevent interaction.
- April updates add a one-time educational prompt and a connection-time security dialog that disables local resource redirections by default and shows publisher and redirection details.
- RDP files are commonly abused in phishing campaigns, with groups like APT29 using them to steal documents and credentials.
- Users reported KB5083769 caused third-party backup failures on Windows 11 due to a VSS timeout, and Microsoft issued out-of-band fixes for related server issues.