Página onde o captcha ficará acessivel.

page.xhtml

<h:panelGroup id="pnl_captcha" rendered="#{comunitarioBean.captchaVisivel}">
    <div class="row center">
        <p:graphicImage id="img_captcha" value="#{captchaBean.captcha}" cache="false" style="border-radius: 10px"/>
        <p:commandButton class="oButton" icon="ui-icon-refresh"  process="@this" update="img_captcha" title="Atualiza imagem do captcha!"/>
        <p:inputText id="it_captcha" value="#{comunitarioBean.captcha}" style="max-width: 85px">
            <p:ajax process="@this" partialSubmit="true" update="@this"/>
        </p:inputText>
        <p:watermark for="it_captcha" value="Digite aqui!"/></div>
    <div class="row center">
    <small style="font-weight: bold; color: #000">obs.: Digite os caracteres da imagem acima!</small></div>
</h:panelGroup>