Fix Data leakage via the form cache

[#2242801]
[#1780860]
[#1907276]

VCS Label
6.x-1.22
Core compatibility
Release type
Release files
b7fc340347788a8d1115f5660426c84c
Release file SHA-1 hash
95adefa9ac63267fe4c6a8558f54a9c426a4fac3
Release file SHA-256 hash
1c4cbc46e5d72153501ffac41bc0c7da846989443741cd6fb1652d63eaa33531
221ac5660adaa75156d72c9f15fa990b
Release file SHA-1 hash
d54d50607ce38cef8aa8348d29e43cd58b1284d0
Release file SHA-256 hash
64e54a98eaa0afa001fb51ea688f584a646f3519b039da6ba7c63475e4ad7812