Contact Form 7 Update problem

I am using contact form 7 since last 10 years and it was working fine but few years back an update came and i started getting bunch of spam emails and some website breakdown issues as well since then i didnt update the plugin people also reviewing concerns after update the version i have now is 5.0.5 and i need to update is to the latest version can u plz advice if it is safe to do? your help really appreciated

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