Although the Spectre and Meltdown vulnerabilities are quite serious and Microsoft already issued patches that take care of them, smartphone makers are not that fast. Surprisingly enough, Andry Rubin's Essential Phone is one of the first handsets to get a fix for the two problems mentioned above.
https://www.notebookcheck.net/Essential-Phone-gets-Spectre-and-Meltdown-fix.277224.0.html