diff -up vim82/src/spellsuggest.c.cve0943 vim82/src/spellsuggest.c
--- vim82/src/spellsuggest.c.cve0943	2022-03-28 20:48:07.079197805 +0200
+++ vim82/src/spellsuggest.c	2022-03-28 20:48:07.101197522 +0200
@@ -501,6 +501,10 @@ spell_suggest(int count)
 	    curwin->w_cursor.col = VIsual.col;
 	++badlen;
 	end_visual_mode();
+	// make sure we don't include the NUL at the end of the line
+	line = ml_get_curline();
+	if (badlen > STRLEN(line) - curwin->w_cursor.col)
+	    badlen = STRLEN(line) - curwin->w_cursor.col;
     }
     // Find the start of the badly spelled word.
     else if (spell_move_to(curwin, FORWARD, TRUE, TRUE, NULL) == 0
diff -up vim82/src/testdir/test_spell.vim.cve0943 vim82/src/testdir/test_spell.vim
--- vim82/src/testdir/test_spell.vim.cve0943	2022-03-28 20:48:07.102197509 +0200
+++ vim82/src/testdir/test_spell.vim	2022-03-28 20:49:05.038452974 +0200
@@ -441,6 +441,21 @@ func Test_spellsuggest_expr_errors()
   delfunc MySuggest3
 endfunc
 
+func Test_spellsuggest_visual_end_of_line()
+  let enc_save = &encoding
+  set encoding=iso8859
+
+  " This was reading beyond the end of the line.
+  norm R00000000000
+  sil norm 0
+  sil! norm i00000)
+  sil! norm i00000)
+  call feedkeys("\<CR>")
+  norm z=
+
+  let &encoding = enc_save
+endfunc
+
 func Test_spellinfo()
   new
   let runtime = substitute($VIMRUNTIME, '\\', '/', 'g')