diff --git a/src/plugins/vis_default_editor/public/_default.scss b/src/plugins/vis_default_editor/public/_default.scss
index 2187baea547da..25220c322c8ff 100644
--- a/src/plugins/vis_default_editor/public/_default.scss
+++ b/src/plugins/vis_default_editor/public/_default.scss
@@ -70,8 +70,7 @@
 
 .visEditor__visualization {
   display: flex;
-  flex-basis: 100%;
-  flex: 1;
+  flex: 1 1 auto;
   overflow: hidden;
 
   @include euiBreakpoint('xs', 's', 'm') {
diff --git a/src/plugins/vis_default_editor/public/_sidebar.scss b/src/plugins/vis_default_editor/public/_sidebar.scss
index ed92dc1dae884..42f7c4e6a892c 100644
--- a/src/plugins/vis_default_editor/public/_sidebar.scss
+++ b/src/plugins/vis_default_editor/public/_sidebar.scss
@@ -4,6 +4,11 @@
 
 .visEditorSidebar {
   min-width: $vis-editor-sidebar-min-width;
+
+  // a hack for IE, issue: https://github.com/elastic/kibana/issues/66586
+  > .visEditorSidebar__formWrapper {
+    flex-basis: auto;
+  }
 }
 
 .visEditorSidebar__form {
diff --git a/src/plugins/vis_default_editor/public/components/sidebar/sidebar.tsx b/src/plugins/vis_default_editor/public/components/sidebar/sidebar.tsx
index 9dfeae1815d1a..68b7ab06c4875 100644
--- a/src/plugins/vis_default_editor/public/components/sidebar/sidebar.tsx
+++ b/src/plugins/vis_default_editor/public/components/sidebar/sidebar.tsx
@@ -177,7 +177,7 @@ function DefaultEditorSideBar({
         gutterSize="none"
         responsive={false}
       >
-        <EuiFlexItem>
+        <EuiFlexItem className="visEditorSidebar__formWrapper">
           <form
             className="visEditorSidebar__form"
             name="visualizeEditor"