diff --git a/shared-bindings/displayio/Group.c b/shared-bindings/displayio/Group.c
index 94ee2e58de1..702b1fca8e0 100644
--- a/shared-bindings/displayio/Group.c
+++ b/shared-bindings/displayio/Group.c
@@ -87,7 +87,7 @@ MP_DEFINE_CONST_FUN_OBJ_1(displayio_group_get_scale_obj, displayio_group_obj_get
 static mp_obj_t displayio_group_obj_set_scale(mp_obj_t self_in, mp_obj_t scale_obj) {
     displayio_group_t *self = native_group(self_in);
 
-    mp_int_t scale = mp_arg_validate_int_min(mp_obj_get_int(scale_obj), 1, MP_QSTR_scale);
+    mp_int_t scale = mp_arg_validate_int_range(mp_obj_get_int(scale_obj), 1, 32767, MP_QSTR_scale);
 
     common_hal_displayio_group_set_scale(self, scale);
     return mp_const_none;
diff --git a/shared-bindings/displayio/TileGrid.c b/shared-bindings/displayio/TileGrid.c
index fb5cabf05bf..bc751b472a9 100644
--- a/shared-bindings/displayio/TileGrid.c
+++ b/shared-bindings/displayio/TileGrid.c
@@ -110,6 +110,8 @@ static mp_obj_t displayio_tilegrid_make_new(const mp_obj_type_t *type, size_t n_
     }
     mp_obj_t pixel_shader = args[ARG_pixel_shader].u_obj;
     displayio_tilegrid_validate_pixel_shader(pixel_shader);
+    mp_arg_validate_int_range(args[ARG_tile_width].u_int, 0, 0xffff, MP_QSTR_tile_width);
+    mp_arg_validate_int_range(args[ARG_tile_height].u_int, 0, 0xffff, MP_QSTR_tile_height);
     uint16_t tile_width = args[ARG_tile_width].u_int;
     if (tile_width == 0) {
         tile_width = bitmap_width;
@@ -118,6 +120,8 @@ static mp_obj_t displayio_tilegrid_make_new(const mp_obj_type_t *type, size_t n_
     if (tile_height == 0) {
         tile_height = bitmap_height;
     }
+    mp_arg_validate_int_min(tile_width, 1, MP_QSTR_tile_width);
+    mp_arg_validate_int_min(tile_height, 1, MP_QSTR_tile_height);
     if (bitmap_width % tile_width != 0) {
         mp_raise_ValueError(MP_ERROR_TEXT("Tile width must exactly divide bitmap width"));
     }
@@ -125,12 +129,23 @@ static mp_obj_t displayio_tilegrid_make_new(const mp_obj_type_t *type, size_t n_
         mp_raise_ValueError(MP_ERROR_TEXT("Tile height must exactly divide bitmap height"));
     }
 
+    mp_arg_validate_int_range(args[ARG_width].u_int, 1, 0xffff, MP_QSTR_width);
+    mp_arg_validate_int_range(args[ARG_height].u_int, 1, 0xffff, MP_QSTR_height);
+
+    uint16_t bitmap_width_in_tiles = bitmap_width / tile_width;
+    uint16_t bitmap_height_in_tiles = bitmap_height / tile_height;
+    uint32_t tiles_in_bitmap = (uint32_t)bitmap_width_in_tiles * bitmap_height_in_tiles;
+    mp_arg_validate_length_min(tiles_in_bitmap, 1, MP_QSTR_bitmap);
+
+    mp_arg_validate_int_range(args[ARG_default_tile].u_int, 0,
+        (mp_int_t)tiles_in_bitmap - 1, MP_QSTR_default_tile);
+
     int16_t x = args[ARG_x].u_int;
     int16_t y = args[ARG_y].u_int;
 
     displayio_tilegrid_t *self = mp_obj_malloc(displayio_tilegrid_t, &displayio_tilegrid_type);
     common_hal_displayio_tilegrid_construct(self, bitmap,
-        bitmap_width / tile_width, bitmap_height / tile_height,
+        bitmap_width_in_tiles, bitmap_height_in_tiles,
         pixel_shader, args[ARG_width].u_int, args[ARG_height].u_int,
         tile_width, tile_height, x, y, args[ARG_default_tile].u_int);
 
diff --git a/shared-bindings/tilepalettemapper/TilePaletteMapper.c b/shared-bindings/tilepalettemapper/TilePaletteMapper.c
index c22ea47bf26..a4438bb1eca 100644
--- a/shared-bindings/tilepalettemapper/TilePaletteMapper.c
+++ b/shared-bindings/tilepalettemapper/TilePaletteMapper.c
@@ -45,6 +45,8 @@ static mp_obj_t tilepalettemapper_tilepalettemapper_make_new(const mp_obj_type_t
         mp_raise_TypeError_varg(MP_ERROR_TEXT("unsupported %q type"), MP_QSTR_pixel_shader);
     }
 
+    mp_arg_validate_int_min(args[ARG_input_color_count].u_int, 1, MP_QSTR_input_color_count);
+
     tilepalettemapper_tilepalettemapper_t *self = mp_obj_malloc(tilepalettemapper_tilepalettemapper_t, &tilepalettemapper_tilepalettemapper_type);
     common_hal_tilepalettemapper_tilepalettemapper_construct(self, pixel_shader, args[ARG_input_color_count].u_int);
 
@@ -128,9 +130,12 @@ static mp_obj_t tilepalettemapper_subscr(mp_obj_t self_in, mp_obj_t index_obj, m
     } else {
         uint16_t x = 0;
         uint16_t y = 0;
+        uint16_t width = common_hal_tilepalettemapper_tilepalettemapper_get_width(self);
+        if (width == 0) {
+            mp_raise_IndexError(MP_ERROR_TEXT("Tile index out of bounds"));
+        }
         if (mp_obj_is_small_int(index_obj)) {
             mp_int_t i = MP_OBJ_SMALL_INT_VALUE(index_obj);
-            uint16_t width = common_hal_tilepalettemapper_tilepalettemapper_get_width(self);
             x = i % width;
             y = i / width;
         } else {
diff --git a/shared-module/displayio/Group.c b/shared-module/displayio/Group.c
index 84ebffdab6d..1f6d8034b5e 100644
--- a/shared-module/displayio/Group.c
+++ b/shared-module/displayio/Group.c
@@ -187,7 +187,8 @@ void displayio_group_update_transform(displayio_group_t *self,
         self->absolute_transform.mirror_x = parent_transform->mirror_x;
         self->absolute_transform.mirror_y = parent_transform->mirror_y;
 
-        self->absolute_transform.scale = parent_transform->scale * self->scale;
+        uint32_t combined = (uint32_t)parent_transform->scale * self->scale;
+        self->absolute_transform.scale = combined > UINT16_MAX ? UINT16_MAX : (uint16_t)combined;
     }
     _update_child_transforms(self);
 }
@@ -197,10 +198,11 @@ void common_hal_displayio_group_set_scale(displayio_group_t *self, uint32_t scal
         return;
     }
     check_readonly(self);
-    uint8_t parent_scale = self->absolute_transform.scale / self->scale;
+    uint16_t parent_scale = self->absolute_transform.scale / self->scale;
     self->absolute_transform.dx = self->absolute_transform.dx / self->scale * scale;
     self->absolute_transform.dy = self->absolute_transform.dy / self->scale * scale;
-    self->absolute_transform.scale = parent_scale * scale;
+    uint32_t combined = (uint32_t)parent_scale * scale;
+    self->absolute_transform.scale = combined > UINT16_MAX ? UINT16_MAX : (uint16_t)combined;
     self->scale = scale;
     _update_child_transforms(self);
 }
diff --git a/shared-module/displayio/Palette.c b/shared-module/displayio/Palette.c
index 968296c69f1..bb0035f1eb5 100644
--- a/shared-module/displayio/Palette.c
+++ b/shared-module/displayio/Palette.c
@@ -55,7 +55,7 @@ uint32_t common_hal_displayio_palette_get_color(displayio_palette_t *self, uint3
 
 void displayio_palette_get_color(displayio_palette_t *self, const _displayio_colorspace_t *colorspace, const displayio_input_pixel_t *input_pixel, displayio_output_pixel_t *output_color) {
     uint32_t palette_index = input_pixel->pixel;
-    if (palette_index > self->color_count || self->colors[palette_index].transparent) {
+    if (palette_index >= self->color_count || self->colors[palette_index].transparent) {
         output_color->opaque = false;
         return;
     }
diff --git a/shared-module/displayio/TileGrid.c b/shared-module/displayio/TileGrid.c
index b5c691ccbd6..f0365e9b08f 100644
--- a/shared-module/displayio/TileGrid.c
+++ b/shared-module/displayio/TileGrid.c
@@ -22,7 +22,9 @@ void common_hal_displayio_tilegrid_construct(displayio_tilegrid_t *self, mp_obj_
     mp_obj_t pixel_shader, uint16_t width, uint16_t height,
     uint16_t tile_width, uint16_t tile_height, uint16_t x, uint16_t y, uint16_t default_tile) {
 
-    uint32_t total_tiles = width * height;
+    uint32_t total_tiles = (uint32_t)width * (uint32_t)height;
+    mp_arg_validate_length_max(total_tiles, SIZE_MAX / sizeof(uint16_t),
+        MP_QSTR_TileGrid);
     self->bitmap_width_in_tiles = bitmap_width_in_tiles;
     self->tiles_in_bitmap = bitmap_width_in_tiles * bitmap_height_in_tiles;
 
diff --git a/shared-module/displayio/area.h b/shared-module/displayio/area.h
index eed54613a5a..88c952e58e3 100644
--- a/shared-module/displayio/area.h
+++ b/shared-module/displayio/area.h
@@ -23,9 +23,9 @@ struct _displayio_area_t {
 typedef struct {
     uint16_t x;
     uint16_t y;
-    int8_t dx;
-    int8_t dy;
-    uint8_t scale;
+    int16_t dx;
+    int16_t dy;
+    uint16_t scale;
     uint16_t width;
     uint16_t height;
     bool mirror_x;
diff --git a/shared-module/tilepalettemapper/TilePaletteMapper.c b/shared-module/tilepalettemapper/TilePaletteMapper.c
index 13711b2c253..bb0a0acc199 100644
--- a/shared-module/tilepalettemapper/TilePaletteMapper.c
+++ b/shared-module/tilepalettemapper/TilePaletteMapper.c
@@ -67,6 +67,10 @@ void tilepalettemapper_tilepalettemapper_get_color(tilepalettemapper_tilepalette
         }
         return;
     }
+    if (input_pixel->pixel >= self->input_color_count) {
+        output_color->opaque = false;
+        return;
+    }
     uint16_t tile_index = y_tile_index * self->width_in_tiles + x_tile_index;
     uint32_t mapped_index = self->tile_mappings[tile_index][input_pixel->pixel];
     displayio_input_pixel_t tmp_pixel;
diff --git a/shared-module/vectorio/Polygon.c b/shared-module/vectorio/Polygon.c
index 212d519e298..0c5c487b156 100644
--- a/shared-module/vectorio/Polygon.c
+++ b/shared-module/vectorio/Polygon.c
@@ -31,6 +31,7 @@ static void _clobber_points_list(vectorio_polygon_t *self, mp_obj_t points_tuple
     if (len < 3) {
         mp_raise_TypeError(MP_ERROR_TEXT("Polygon needs at least 3 points"));
     }
+    mp_arg_validate_length_range(len, 3, UINT16_MAX / 2, MP_QSTR_points);
 
     int16_t *points_list = gc_realloc(self->points_list, 2 * len * sizeof(uint16_t), true);
     VECTORIO_POLYGON_DEBUG("realloc(%p, %d) -> %p", self->points_list, 2 * len * sizeof(uint16_t), points_list);
@@ -39,7 +40,7 @@ static void _clobber_points_list(vectorio_polygon_t *self, mp_obj_t points_tuple
     self->points_list = NULL;
     self->len = 0;
 
-    for (uint16_t i = 0; i < len; ++i) {
+    for (size_t i = 0; i < len; ++i) {
         size_t tuple_len = 0;
         mp_obj_t *tuple_items;
         mp_arg_validate_type(items[i], &mp_type_tuple, MP_QSTR_point);