diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index c77f00a979..e489d43675 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,9 @@
+2017-06-15  Nick Clifton  <nickc@redhat.com>
+
+	PR binutils/21595
+	* aarch64-dis.c (aarch64_ext_ldst_reglist): Check for an out of
+	range value.
+
 2017-06-15  Nick Clifton  <nickc@redhat.com>
 
 	PR binutils/21588
diff --git a/opcodes/aarch64-dis.c b/opcodes/aarch64-dis.c
index 27ef22bc09..a860dbcb00 100644
--- a/opcodes/aarch64-dis.c
+++ b/opcodes/aarch64-dis.c
@@ -409,6 +409,9 @@ aarch64_ext_ldst_reglist (const aarch64_operand *self ATTRIBUTE_UNUSED,
   info->reglist.first_regno = extract_field (FLD_Rt, code, 0);
   /* opcode */
   value = extract_field (FLD_opcode, code, 0);
+  /* PR 21595: Check for a bogus value.  */
+  if (value >= ARRAY_SIZE (data))
+    return 0;
   if (expected_num != data[value].num_elements || data[value].is_reserved)
     return 0;
   info->reglist.num_regs = data[value].num_regs;