Coraza before 3.8.1 extracts multipart upload filenames with Go's mime.ParseMediaType, which silently ignores RFC 5987 filename parameters whose charset is not utf-8 or us-ascii. Unauthenticated attackers can send a decoy filename with filename=iso-8859-1''shell.php, or filename alone, so FILES-based rules never see the real name, letting dangerous uploads reach backends that honor filename.

Coraza from 3.0.4 before 3.8.1 contains a request body inspection bypass because request-body processor selection compares the entire Content-Type value exactly, so URL-encoded bodies whose Content-Type carries a media-type parameter are never parsed. Unauthenticated attackers can send application/x-www-form-urlencoded; charset=UTF-8 to keep ARGSPOST and REQUESTBODY empty, evading body rules while the backend still processes the payload.

Coraza from 3.0.0 before 3.8.1 has a JSON body processor that flattens nested properties into dot-separated ARGSPOST names without escaping literal dots, so distinct properties collide. Unauthenticated attackers can add a later dotted property such as account.role that overwrites a malicious nested value, hiding SQL injection payloads from OWASP CRS rules while backends still receive them.