Issues

• CheckBox/RadioButton glyph disappears when Image is set in VisualStylesMode.Net11

  NewApi-Net11untriaged
  dotnet/winforms#15267 · Filter by author Amy-Li03 opened on Oct 14, 2026
  

• Mouse-focused control displays focus border only after Tab navigation has been used

  untriaged
  dotnet/winforms#15266 · Filter by author Olina-Zhang opened on Oct 14, 2026
  1

  

• CheckBox/RadioButton not display the image when setting the Appearance as ToggleSwitch in NET 11 mode

  NewApi-Net11untriaged
  dotnet/winforms#15265 · Filter by author Zheng-Li01 opened on Oct 14, 2026
  

• WinForms VB templates trigger WFO3002 warnings with the .NET 11 design-time analyzer

  area-VisualBasic
  dotnet/winforms#15251 · Filter by author Olina-Zhang opened on Oct 9, 2026
  3

  

• A component with PropertyTabAttribute and PropertyTabScope set to "Document" does not add a property tab.

  area-controls-PropertyGrid
  dotnet/winforms#15227 · Filter by author aerworker opened on Oct 6, 2026
  1

  

• System.Drawing.Drawing2D.Matrix.Transform*(ReadOnlySpan) methods mutate the ReadOnlySpan

  api-suggestionuntriaged
  dotnet/winforms#15226 · Filter by author rickbrew opened on Oct 6, 2026
  1

• Regression: Bitmap finalized during Image.Save(Stream, ImageFormat) leaks native GDI+ memory

  area-System.Drawing🪲 bug💥 regression-release
  dotnet/winforms#15213 · Filter by author avendel opened on Sep 30, 2026
  1

  

• DomainUpDown and NumericUpDown allow height changes in VisualStylesMode.Net11 instead of reverting to the original height

  NewApi-Net11
  dotnet/winforms#15210 · Filter by author Olina-Zhang opened on Sep 30, 2026
  

• CheckBox and RadioButton do not raise the UIA events for their state changes (ToggleState, ElementSelected), unlike on .NET Framework

  untriaged
  dotnet/winforms#15201 · Filter by author kastwey opened on Sep 27, 2026
  

• DefaultPageSettings.PaperSize can terminate the process with 0xc0000005 for an offline printer queue

  🪲 bug
  dotnet/winforms#15200 · Filter by author hyigit-adelcon opened on Sep 25, 2026
  1

• DataObject payload leaked after drag and drop: ComHelpers.GetObjectForIUnknown<T> QueryInterface(IUnknown) is never released (EnumFormatEtc)

  🪲 bug💥 regression-release
  dotnet/winforms#15199 · Filter by author cuiliang opened on Sep 25, 2026
  3

• TreeNodeCollection indexer setter throws NullReferenceException for a TreeNode not attached to a TreeView (regression since .NET 6)

  💥 regression-framework💥 regression-releaseuntriaged
  dotnet/winforms#15190 · Filter by author ricardobossan opened on Sep 23, 2026
  

• A ContextMenuStrip opened from the keyboard is silent for screen readers (no MenuOpened the first time, no item focused)

  dotnet/winforms#15178 · Filter by author kastwey opened on Sep 22, 2026
  

• When DataGridView has a lot of rows, selecting row near bottom of DataGridView is very slow

  tenet-accessibility
  dotnet/winforms#15171 · Filter by author hjin1113-web opened on Sep 22, 2026
  

• Selected state is not announced for combo Box options.: A11y_Winform_Input_NameRoleValue

  a11y-externalwaiting-author-feedback💤 no-recent-activity
  dotnet/winforms#15169 · Filter by author PoojaNamde opened on Sep 21, 2026
  4

  

• Test Category combobox lacks visible label.: A11y_Winform_Inputs_Labels or Instructions

  waiting-author-feedback💤 no-recent-activity
  dotnet/winforms#15168 · Filter by author PoojaNamde opened on Sep 21, 2026
  6

  

• Keyboard focus does not reach grid column headers, preventing access to sorting and column width adjustment.: A11y_Winform_ListTreeGrid_Keyboard

  waiting-author-feedback💤 no-recent-activity
  dotnet/winforms#15167 · Filter by author PoojaNamde opened on Sep 21, 2026
  2

  

• [Dark Mode] The dotnet line of button is black in DarkMode

  area-DarkMode💥 regression-preview
  dotnet/winforms#15162 · Filter by author Zheng-Li01 opened on Sep 21, 2026
  

• RescaleConstantsForDpi method provide parameters incorrect

  area-HDPI-PMv2waiting-on-team
  dotnet/winforms#15144 · Filter by author chenYL123djdj opened on Sep 18, 2026
  1

  

• FormRevealMode.Inherit always resolves to Classic instead of inheriting the expected reveal mode

  NewApi-Net11untriaged
  dotnet/winforms#15139 · Filter by author Olina-Zhang opened on Sep 17, 2026
  

• RichTextBox/TextBox scrollbar is rendered incorrectly after changing DPI

  NewApi-Net11untriaged
  dotnet/winforms#15129 · Filter by author Olina-Zhang opened on Sep 16, 2026

• [125% DPI] TextBox and MaskedTextBox render incorrect bottom border and accent focus stroke

  NewApi-Net11untriaged
  dotnet/winforms#15128 · Filter by author Olina-Zhang opened on Sep 16, 2026
  

• CheckBox and RadioButton with Appearance.Button and FlatStyle.Standard do not use the system accent color when checked in Dark Mode

  NewApi-Net11untriaged
  dotnet/winforms#15126 · Filter by author Olina-Zhang opened on Sep 16, 2026

• CheckBox and RadioButton ToggleSwitch render the thumb in black instead of white when checked in non-Dark Mode

  NewApi-Net11waiting-on-team
  dotnet/winforms#15125 · Filter by author Olina-Zhang opened on Sep 16, 2026
  1

  

• GroupBox with BackgroundImage flickers and responds slowly when selecting child controls at design time in VisualStylesMode.Net11

  NewApi-Net11untriaged
  dotnet/winforms#15124 · Filter by author Olina-Zhang opened on Sep 16, 2026