Question regarding user logout workflow

[Amit Dongaonkar]

Hi Group,
I have a question about the user logout workflow.

We have Shibb SP servicing users coming to our platform. During a penetration testing exercise an observation was raised as follows:

When a user hits the logout button on the application he is logged out but when he enters the application URL again in the browser then he is able to get into the application again without get redirected to the IdP for authentication.

Looking at the SAML assertion received for the user I see the following
        <saml:AuthnStatement SessionIndex="wcfENW_JyI4mCzIxCTeGEo-oH6."
                             SessionNotOnOrAfter="2026-04-17T20:32:43.689Z"
                             AuthnInstant="2026-04-17T15:02:43.460Z"
                             >
So the IdP is saying that the session is valid for roughly 5 hours.

Since the user is trying to access the application as soon as he logs out and its well within 5 hours the application is letting the user in again. Also I see the application sending a auth request to the IdP this time around before letting the user in.

Question: Is this the right behavior and the observation from the pen testing is not valid, if not, then is there a way to invalidate the session once the user logs out from the application so that he is redirected to the IdP for authentication?

Note that we don't have a Single Logout (SLO) URL from the IdP and I prefer to not use it as it will throw him out of all other applications (that's my understanding).

Would appreciate any guidance on this.


Thanks
Amit Dongaonkar

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