Extensions inside your editor can read your repo and your tokens, so they are part of your supply chain. This week that stopped being theoretical.
A report on backdoors in official Claude Code extensions sat on the Hacker News front page on 30 October. I am not going to speculate beyond what was published, but the shape of the risk is familiar: an extension running in the editor sees your source and your environment variables, plus whatever credentials you happen to have loaded.
So treat extensions like dependencies. Pin versions, keep an inventory of what is installed, then rotate any credential the editor could have read.
If you want someone to walk your payment and account flows and check what a compromised dev machine could actually reach, that is a security review I do: https://polycratia.com/c/302db13a and you get cost and timeline within a day.