Another day, another long-term, critical, and likely unpatchable flaw in consumer and business routers is exposed. See https://www.cpomagazine.com/cyber-security/12-year-old-router-vulnerability-discovered-affecting-millions-of-devices-exposing-serious-supply-chain-risks/
As I have said repeatedly, the software in most consumer routers is crap, and this is being generous. Not only is it crap to begin with, even when critical flaws are discovered and exposed it can take years for them to be patched by the manufacturer if they are ever patched at all. And even if they are, most of their customers never know about these patches as there is no notification mechanism or means to automatically push the patches to the user’s devices.
If you want to have a modicum of confidence in the security of your home network, you need to build and/or purchase your own firewall or invest in a commercial firewall that is financially prohibitive. Even then, almost all homeowners lack the networking skills to set up and manage a commercial-grade firewall.
What can you do? Frankly, this old recommendation from Gibson Research https://www.grc.com/nat/nats.htm is still the cheapest and simplest solution to strengthening most home networks, with the caveat that if you are a hardcore gamer or depend on devices in your network that use UPNP (a terrible idea), then this will break things and not work for you.