Microsoft confirmed that April 2026 cumulative updates introduced a known issue causing Remote Desktop (.rdp) security warning dialogs to display incorrectly on supported Windows versions. On multi-monitor systems with differing display scaling, warning text can overlap and buttons may be hidden or misplaced, hindering interaction with the new RDP safety prompts. #RDP #APT29
Keypoints
- The issue affects all supported Windows versions, including the April 2026 updates for Windows 11, Windows 10, and Windows Server.
- Microsoft added a one-time educational prompt and a security dialog to surface RDP file publisher, remote address, and resource redirections.
- The display problem occurs when using multiple monitors with different scaling settings, causing overlapping text and misplaced buttons.
- Unsigned RDP files are shown as “Caution: Unknown remote connection,” while signed files display the publisher for user verification.
- Threat actors such as APT29 have abused RDP files in phishing campaigns, prompting these protective changes.