There appears to be some disagreement/confusion about the precise meaning of セレブ - some dictionaries claim that セレブ means the same thing as English "celebrity", while others claim that it just means "rich person".
デジタル大辞泉 basically says it means the same as "celebrity" - a famous person.
著名人。名士。セレブリティー。
語源由来辞典 suggests that while it can mean "famous person", it is also frequently used to refer to a "beautiful woman" or a "rich person".
セレブとは、名士。有名人。女性誌などでは、知名度に関係なく、美しく優雅で知的な女性を意味したり、お金持ちをさすことが多い。
The explanation on Japanese Wikipedia also says that セレブ implies things like "rich", "refined", and "posh" (albeit this section lacks sources).
日本のテレビや雑誌メディアはセレブと略し、金持ち、優雅な、高級な、などの意味合いで使用している。
Given that this word is a relatively recent import from English (late '90s, according to 語源由来辞典), I'm guessing that there's still some variation in the way it's used. In any case, what I would like to know is - how is セレブ typically used these days? Does it mean "celebrity", or does it mean "rich person", or can it mean both, or what?