diff --git a/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c b/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
index 37db8e8d081..675f549501a 100644
--- a/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
+++ b/subsys/bluetooth/controller/ll_sw/ull_adv_aux.c
@@ -194,13 +194,27 @@ uint8_t ll_adv_aux_sr_data_set(uint8_t handle, uint8_t op, uint8_t frag_pref, ui
 	 */
 	pri_pdu_prev = lll_adv_data_peek(lll);
 	if (pri_pdu_prev->type != PDU_ADV_TYPE_EXT_IND) {
+		if ((op != BT_HCI_LE_EXT_ADV_OP_COMPLETE_DATA) || (len > 31)) {
+			return BT_HCI_ERR_INVALID_PARAM;
+		}
 		return ull_scan_rsp_set(adv, len, data);
 	}
 
+	/* Can only set complete data and cannot discard data on enabled set */
+	if (adv->is_enabled && ((op != BT_HCI_LE_EXT_ADV_OP_COMPLETE_DATA) ||
+				(len == 0))) {
+		return BT_HCI_ERR_CMD_DISALLOWED;
+	}
+
 	LL_ASSERT(lll->aux);
 	aux_pdu = lll_adv_aux_data_peek(lll->aux);
 	sr_prev = lll_adv_scan_rsp_peek(lll);
 
+	/* Can only discard data on non-scannable instances */
+	if (!(aux_pdu->adv_ext_ind.adv_mode & BT_HCI_LE_ADV_PROP_SCAN) && len) {
+		return BT_HCI_ERR_INVALID_PARAM;
+	}
+
 	/* Update scan response PDU fields. */
 	sr_pdu = lll_adv_scan_rsp_alloc(lll, &idx);
 	sr_pdu->type = PDU_ADV_TYPE_AUX_SCAN_RSP;