When a user logs out the current user session is destroyed and no new pages can be loaded for which a user must be logged in. However, when you hit the 'back' button on your browser, it typically retrieves the page from the local cache. There is no contact with the server to see if the current session is still valid.

So, what you need to do is detect whether the backspace button has been hit and in that case check the validity of the session. This means there must be a piece of javacript included in the page, because this action needs to take place at the user side. I'm not a security expert, but the common way to detect the backspace goes like this:

window.onhashchange = function() {
 .. your action ..
 }

There are some snags to this method. Now, your action must be to call back to the server. That question has been answered before here on WPSE.

When a user logs out the current user session is destroyed and no new pages can be loaded for which a user must be logged in. However, when you hit the 'back' button on your browser, it typically retrieves the page from the local cache. There is no contact with the server to see if the current session is still valid.

So, what you need to do is detect whether the backspace button has been hit and in that case check the validity of the session. This means there must be a piece of javacript included in the page, because this action needs to take place at the user side. I'm not a security expert, but the common way to detect the backspace goes like this:

window.onhashchange = function() {
 .. your action ..
 }

There are some snags to this method. Now, your action must be to call back to the server. That question has been answered before here on WPSE.

When a user logs out the current user session is destroyed and no new pages can be loaded for which a user must be logged in. However, when you hit the 'back' button on your browser, it typically retrieves the page from the local cache. There is no contact with the server to see if the current session is still valid.

So, what you need to do is detect whether the backspace button has been hit and in that case check the validity of the session. This means there must be a piece of javacript included in the page, because this action needs to take place at the user side. I'm not a security expert, but the common way to detect the backspace goes like this:

window.onhashchange = function() {
 .. your action ..
 }

There are some snags to this method. Now, your action must be to call back to the server. That question has been answered before here on WPSE.

When a user logs out the current user session is destroyed and no new pages can be loaded for which a user must be logged in. However, when you hit the 'back' button on your browser, it typically retrieves the page from the local cache. There is no contact with the server to see if the current session is still valid.

So, what you need to do is detect whether the backspace button has been hit and in that case check the validity of the session. This means there must be a piece of javacript included in the page, because this action needs to take place at the user side. I'm not a security expert, but the common way to detect the backspace goes like this:

window.onhashchange = function() {
 .. your action ..
 }

There are some snags to this method. Now, your action must be to call back to the server. That question has been answered before here on WPSE.