Several vulnerabilities were discovered in Heimdal, an implementation of Kerberos 5 that aims to be compatible with MIT Kerberos. CVE-2018-16860 Isaac Boukris and Andrew Bartlett discovered that Heimdal was susceptible to man-in-the-middle attacks caused by incomplete checksum validation. Details on the issue can be found in the Samba advisory at https://www.samba.org/samba/security/CVE-2018-16860.html CVE-2019-12098 It was discovered that failure of verification of the PA-PKINIT-KX key exchange client-side could permit to perform man-in-the-middle attack.