Ist der Satz richtig?
Das ist eine bloße Vorsichtsmaßnahme.

Sehen Sie eine Übersetzung

It's grammatically correct, but I think the word choice could maybe be better

the word "bloß", when used as an adjective in front of a noun like here has a negative connotation, like saying "this is nothing but...", as if you're exposing something for what it truly is.

for example people might say "das ist bloßer Betrug" meaning "this is nothing but a scam"; "das ist bloße Abzocke" etc.

I don't think that this is the meaning you're going for here, so I would phrase this as:
"Das ist eine einfache Vorsichtsmaßnahme"

As the other comment said however, you can also say it like "Das ist bloß eine Vorsichtsmaßnahme", then it doesn't have this negative connotation. If you use the word "bloß" like this (unconjugated, like a partice) it's exactly like the english word "just/only"

e.g. Ich bin bloß hier um einzukaufen - I am just here to buy something

So it changes meaning depending on how you use it.

There is another outdated meaning of the word meaning: naked, bare, exposed. You will mostly find it in sayings and expressions nowdays like for example:

"Ich habe ihn mit meinem bloßen Auge gesehen" - "I saw him with my bare eye"

also: "jemanden bloß stellen"- "to embarrass someone", very common expression