Little Snitch versions 4.0 to 4.0.6 use the SecStaticCodeCheckValidityWithErrors() function without the kSecCSCheckAllArchitectures flag and therefore do not validate all architectures stored in a fat binary. An attacker can maliciously craft a fat binary containing multiple architectures that may cause a situation where Little Snitch treats the running process as having no code signature at all while erroneously indicating that the binary on disk does have a valid code signature. This could lead to users being confused about whether or not the code signature is valid.
https://www.okta.com/security-blog/2018/06/issues-around-third-party-apple-code-signing-checks/