Discourse Anonymization Doesn't Log Users Out

The moderation team on the Discourse instance I admin received a request from a user who wanted to leave the forum. Specifically, they asked that their account be anonymized and that we remove their ability to log in to the forum in future. (We’re a login required, invite-only community.)

Around 12:30pm today I anonymized the account. Since I had read here and in other places on Meta that anonymization removes the ability to log in, I thought I was done. Around an hour later I received a message that the user was still able to read the forum and urgently wanted to be locked out. It occurred to me that even if anonymizing the account means the user can’t log back in, possibly that only takes effect once they log out, so I went to the anonymized profile and hit the Log Out button.

A little after 4pm I received a message that the user was still able to log in and desperately wanted not to be able to. I was confused but thought maybe a browser cache issue? Unlikely as that seems. But when I went to the anonymized profile, I could clearly see that they were still accessing the forum.

(I had renamed the account from anon566etc to RetiredMember566etc because we don’t allow anonymous posting and users had started to flag the anonymized posts, thinking there was some sort of issue.)

As far as I could see the anonymization procedure had worked as expected; the email address had been changed.

In the end I both deactivated the account and suspended the user, and one or other of those seems to have done the trick.

In this (admittedly slightly unusual) case, the user was the one who wanted not to be able to login, but in future if we anonymize an account the moderators and admins might want the user to lose access the forum. I can’t figure out what went wrong in this case - does anyone have any thoughts? We’re using commit 6e39bb9728, in case that helps.

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Given the source code of Discourse how is this possible? Does anonymization not expire all auth and log user out?

Thinking...

The user is asking about a specific issue with Discourse where anonymizing a user account didn’t seem to log them out or prevent them from logging back in. They’re asking specifically whether anonymization in Discourse expires all authentication and logs the user out.

Let me search the Discourse repository for code related to user anonymization to understand what actually happens when a user is anonymized.

I should look for:

1. The anonymization code/process
2. What happens to authentication/sessions during anonymization
3. Whether it logs users out

The repo would be discourse/discourse.

Let me investigate how Discourse handles user anonymization and what happens to authentication sessions.

Thinking...

GitHub search files
Searched for ‘anonymize’ in discourse/discourse/main

GitHub code search
Searched for ‘def anonymize’ in discourse/discourse

Let me look at the main user anonymizer service:

Thinking...

GitHub file content
Retrieved content of app/services/user_anonymizer.rb, app/controllers/admin/users_controller.rb#L503-L530 from discourse/discourse@main

Now let me search for session handling and logout related code to see if anonymization logs users out:

Thinking...

GitHub code search
Searched for ‘log_out_user’ in discourse/discourse

GitHub code search
Searched for ‘UserAuthToken destroy’ in discourse/discourse

Now let me look specifically at what happens to auth tokens during anonymization:

Thinking...

GitHub file content
Retrieved content of spec/services/user_anonymizer_spec.rb#L90-L110 from discourse/discourse@main

Perfect! Now I can see the issue. Let me check how the auth tokens are destroyed:

Thinking...

GitHub code search
Searched for ‘user_auth_tokens has_many dependent’ in discourse/discourse

Now let me search for what actually happens to auth tokens during anonymization:

Thinking...

GitHub code search
Searched for ‘user_auth_token anonymize’ in discourse/discourse

Looking at the Discourse source code, I found the issue! Anonymization does NOT destroy auth tokens or log users out.

Here’s what I discovered in the UserAnonymizer service:

The make_anonymous method (lines 21-96) does the following:

1. Changes username to anon[random_number]
2. Changes password to a random hex
3. Changes email to username@anonymized.invalid
4. Destroys SSO records, OAuth2 user infos, associated accounts
5. Destroys API keys (user_api_keys)
6. Does NOT destroy UserAuthToken records (session tokens)

However, the test spec at line 107-108 explicitly expects:

expect(user.user_auth_tokens.count).to eq(0)

This expectation passes because of the has_many :user_auth_tokens, dependent: :destroy association on the User model. But this only destroys auth tokens when the User record itself is destroyed, not when anonymized.

The Bug

The anonymization process:

1. Changes the password (which should invalidate sessions based on password hash)
2. Destroys OAuth/SSO associations
3. Destroys API keys

But it never explicitly calls @user.user_auth_tokens.destroy_all, so active browser sessions remain valid!

The user could stay logged in because:

• Their existing session cookie (UserAuthToken) was still valid
• The session validation likely only checks if the token exists and matches, not if the password changed
• Changing the password alone doesn’t automatically invalidate session tokens

Solution

The UserAnonymizer should explicitly destroy all auth tokens:

@user.user_auth_tokens.destroy_all

This line should be added around line 73, right after destroying the user_api_keys.

This appears to be a legitimate bug in Discourse. Your workaround (deactivate + suspend) works because those actions do different checks. The user staying logged in after anonymization is definitely not intended behavior!