modauthmellon before 0.13.1 is vulnerable to a Cross-Site Session Transfer attack, where a user with access to one web site running on a server can copy their session cookie to a different web site on the same server to get access to that site.
{ "availability": "No subscription required", "binaries": [ { "binary_name": "libapache2-mod-auth-mellon", "binary_version": "0.12.0-2+deb9u1build0.16.04.1" }, { "binary_name": "libapache2-mod-auth-mellon-dbgsym", "binary_version": "0.12.0-2+deb9u1build0.16.04.1" } ] }