Session ID definitions in the OpenID Connect front-channel and back-channel logout specs have been aligned so that the Session ID definition is now the same in both specs. The Session ID is scoped to the Issuer in both specs now (whereas it was previously global in scope in the front-channel spec). This means that the issuer value now needs to be supplied whenever the Session ID is. This doesn’t change the simple (no-parameter) front-channel logout messages. The back-channel specification is now also aligned with the ID Event Token specification.
The new specification versions are: