The `isPublic()` function in the NPM package `ip` doesn't correctly identify certain private IP addresses in uncommon formats such as `0x7F.1` as private. Instead, it reports them as public by returning `true`. This can lead to security issues such as Server-Side Request Forgery (SSRF) if `isPublic()` is used to protect sensitive code paths when passed user input. Versions 1.1.9 and 2.0.1 fix the issue.