reason-jose is a JOSE implementation in ReasonML and OCaml.`Jose.Jws.validate` does not check HS256 signatures. This allows tampering of JWS header and payload data if the service does not perform additional checks. Such tampering could expose applications using reason-jose to authorization bypass. Applications relying on JWS claims assertion to enforce security boundaries may be vulnerable to privilege escalation. This issue has been patched in version 0.8.2.