Is it safe to enable UPnP for gaming, or should I avoid it completely?

I understand your concerns about enabling UPnP. The functionality itself isn't inherently dangerous, but it becomes a risk if your system is infected. If you're seeing those pop-ups, they might be related to an extension or malware—definitely worth checking your system for issues. If you're only enabling UPnP for a few days while you play MW2, just ensure you disable it right after. That way, you minimize the exposure.

Your router should be doing a lot of the heavy lifting in terms of security. Just remember, UPnP can open up a potential vulnerability if malware gets on your computer. To stay safe, I’d suggest running a malware scan to clean your MacBook first. If you do enable UPnP, make sure you monitor your network traffic regularly to see if anything unusual pops up.

UPnP is designed to make things easier for users by allowing devices to request the router to open specific ports as needed. While it has its conveniences, it can pose risks if your devices are compromised. If you don't have any malware and keep your system clean, UPnP should be relatively safe to enable. Just keep an eye on your device security. If you're really concerned, consider just using manual port forwarding instead, even though it's a bit more of a hassle.