diff --git a/source/blender/blenlib/intern/string_cursor_utf8.c b/source/blender/blenlib/intern/string_cursor_utf8.c
index dd3b0a03470..4a9b354ce60 100644
--- a/source/blender/blenlib/intern/string_cursor_utf8.c
+++ b/source/blender/blenlib/intern/string_cursor_utf8.c
@@ -345,6 +345,7 @@ void BLI_str_cursor_step_bounds_utf8(
     const char *str, const int str_maxlen, const int pos, int *r_start, int *r_end)
 {
   BLI_assert(str_maxlen >= 0);
+  BLI_assert(pos >= 0 && pos <= str_maxlen);
   /* Identify the type of characters are on either side of the current cursor position. */
   const eStrCursorDelimType prev = (pos > 0) ? cursor_delim_type_utf8(str, str_maxlen, pos - 1) :
                                                STRCUR_DELIM_NONE;
@@ -373,6 +374,7 @@ void BLI_str_cursor_step_bounds_utf32(
     const char32_t *str, const int str_maxlen, const int pos, int *r_start, int *r_end)
 {
   BLI_assert(str_maxlen >= 0);
+  BLI_assert(pos >= 0 && pos <= str_maxlen);
   /* Identify the type of characters are on either side of the current cursor position. */
   const eStrCursorDelimType prev = (pos > 0) ? cursor_delim_type_unicode(str[pos - 1]) :
                                                STRCUR_DELIM_NONE;
diff --git a/source/blender/editors/interface/interface_handlers.cc b/source/blender/editors/interface/interface_handlers.cc
index 58bca46f5a1..72b5982da89 100644
--- a/source/blender/editors/interface/interface_handlers.cc
+++ b/source/blender/editors/interface/interface_handlers.cc
@@ -3771,14 +3771,21 @@ static void ui_do_but_textedit(
         inbox = ui_searchbox_inside(data->searchbox, event->xy);
       }
 
-      /* for double click: we do a press again for when you first click on button
-       * (selects all text, no cursor pos) */
+      bool is_press_in_button = false;
       if (ELEM(event->val, KM_PRESS, KM_DBL_CLICK)) {
         float mx = event->xy[0];
         float my = event->xy[1];
         ui_window_to_block_fl(data->region, block, &mx, &my);
 
         if (ui_but_contains_pt(but, mx, my)) {
+          is_press_in_button = true;
+        }
+      }
+
+      /* for double click: we do a press again for when you first click on button
+       * (selects all text, no cursor pos) */
+      if (ELEM(event->val, KM_PRESS, KM_DBL_CLICK)) {
+        if (is_press_in_button) {
           ui_textedit_set_cursor_pos(but, data, event->xy[0]);
           but->selsta = but->selend = but->pos;
           data->sel_pos_init = but->pos;
@@ -3798,15 +3805,22 @@ static void ui_do_but_textedit(
 
       /* only select a word in button if there was no selection before */
       if (event->val == KM_DBL_CLICK && had_selection == false) {
-        int selsta, selend;
-        BLI_str_cursor_step_bounds_utf8(data->str, strlen(data->str), but->pos, &selsta, &selend);
-        but->pos = short(selend);
-        but->selsta = short(selsta);
-        but->selend = short(selend);
-        /* Anchor selection to the left side unless the last word. */
-        data->sel_pos_init = ((selend == strlen(data->str)) && (selsta != 0)) ? selend : selsta;
-        retval = WM_UI_HANDLER_BREAK;
-        changed = true;
+        if (is_press_in_button) {
+          const int str_len = strlen(data->str);
+          /* This may not be necessary, additional check to ensure `pos` is never out of range,
+           * since negative values aren't acceptable, see: #113154. */
+          CLAMP(but->pos, 0, str_len);
+
+          int selsta, selend;
+          BLI_str_cursor_step_bounds_utf8(data->str, str_len, but->pos, &selsta, &selend);
+          but->pos = short(selend);
+          but->selsta = short(selsta);
+          but->selend = short(selend);
+          /* Anchor selection to the left side unless the last word. */
+          data->sel_pos_init = ((selend == str_len) && (selsta != 0)) ? selend : selsta;
+          retval = WM_UI_HANDLER_BREAK;
+          changed = true;
+        }
       }
       else if (inbox) {
         /* if we allow activation on key press,