It seems like node supports it with body parser enabled.
But im having trouble finding any docs suggesting anything else supports it on inbound requests.
Obviously there are other scenarios where it is exploitable, but it is a much less severe vuln if the attacker must first force the program to make an outbound request to a server of its chosing rather than just connect to a vulnerable server.
I hope my assets are not connecting to malicious servers, otherwise yes, I have a problem.
DotNet, however, has it's own C# Brotli implementation.
Investigate yourself. Read the documentation. Grep for brotli in the source. Don't blindly trust a chat bot when it says it "might happen in certain configurations".
Unfortunately that means understanding and limiting dependencies of developers... Yea, good luck.
My popcorn is ready. My servers are not.
And don't worry about my stripes, I'm mostly talking about my hobby self-hosted apps. If anything, should someone hack them I'll have a funny article to post on my blog. Professionally, I do things differently.