The library fails to properly validate the `domain` and `path` options, checking them against a permissive RFC 7230 field-content matcher that allows semicolons. Because these values are written into the Set-Cookie header unescaped, an application passing untrusted or request-derived data into these options allows for Set-Cookie attribute injection. This can enable an attacker to override attributes such as `SameSite`, `Secure`, `HttpOnly`, or `Domain` on issued cookies.