[Bug]: After removing a user with occ, some of its related data remains in a few DB tables

⚠️ This issue respects the following points: ⚠️

• This is a bug, not a question or a configuration/webserver/proxy issue.
• This issue is not already reported on Github (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• Nextcloud Server is running on 64bit capable CPU, PHP and OS.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

Hello,

Using Nextcloud 26.0.2 (Yunohost package, but it seems not to be limited to that very package), when deleting a user using occ, I notice that if most of that user data is deleted as expected, some do remains (neither particularly heavy nor sensitve data, but still...) in the following tables

• oc_addressbookchanges
• oc_jobs - this table seems related to logging, probably it is fine not to remove the deleted user's data from there?
• oc_storages
• oc_mail_tags - reported at Nextcloud Mail app's forum
• oc_notifications_settings
  • https://github.com/nextcloud/notifications/pull/1583

Steps to reproduce

1. Create a user testuser
2. Associate an email account to it in Nextcloud Mail app (that may be an optional step)
3. Delete the user using occ user:delete testuser
4. Check mentioned MySQL table to see whether data related to testuser still remain in there.

Expected behavior

I guess all data related to the deleted user should be removed (or at least that there an option is provided to do so)

Installation method

None

Nextcloud Server version

26

Operating system

Debian/Ubuntu

PHP engine version

PHP 8.1

Web server

Nginx

Database engine version

MariaDB

Is this bug present after an update or on a fresh install?

None

Are you using the Nextcloud Server Encryption module?

None

What user-backends are you using?

• Default user-backend (database)
• LDAP/ Active Directory
• SSO - SAML
• Other

Configuration report

{
    "system": {
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "localhost",
            "mydomain.tld"
        ],
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "dbtype": "mysql",
        "version": "25.0.6.1",
        "overwrite.cli.url": "https:\/\/mydomain.tld",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "ldapProviderFactory": "OCA\\User_LDAP\\LDAPProviderFactory",
        "updatechecker": false,
        "memcache.local": "\\OC\\Memcache\\APCu",
        "integrity.check.disabled": true,
        "filelocking.enabled": true,
        "memcache.locking": "\\OC\\Memcache\\Redis",
        "redis": {
            "host": "***REMOVED SENSITIVE VALUE***",
            "port": "5555",
            "timeout": "0.0",
            "password": "***REMOVED SENSITIVE VALUE***"
        },
        "hashing_default_password": true,
        "localstorage.allowsymlinks": true,
        "simpleSignUpLink.shown": false,
        "logout_url": "https:\/\/mydomain.tld\/yunohost\/sso\/?action=logout",
        "maintenance": false,
        "loglevel": 2
    }
}

List of activated Apps

Enabled:
  - calendar: 4.3.4
  - circles: 25.0.0
  - cloud_federation_api: 1.8.0
  - comments: 1.15.0
  - contactsinteraction: 1.6.0
  - dashboard: 7.5.0
  - dav: 1.24.0
  - federatedfilesharing: 1.15.0
  - federation: 1.15.0
  - files: 1.20.1
  - files_external: 1.17.0
  - files_mindmap: 0.0.28
  - files_pdfviewer: 2.6.0
  - files_rightclick: 1.4.0
  - files_sharing: 1.17.0
  - files_trashbin: 1.15.0
  - files_versions: 1.18.0
  - firstrunwizard: 2.14.0
  - forms: 3.3.0
  - logreader: 2.10.0
  - lookup_server_connector: 1.13.0
  - mail: 2.2.6
  - nextcloud_announcements: 1.14.0
  - notifications: 2.13.1
  - oauth2: 1.13.0
  - password_policy: 1.15.0
  - photos: 2.0.1
  - polls: 5.0.5
  - privacy: 1.9.0
  - provisioning_api: 1.15.0
  - ransomware_protection: 1.14.0
  - recommendations: 1.4.0
  - related_resources: 1.0.4
  - serverinfo: 1.15.0
  - settings: 1.7.0
  - sharebymail: 1.15.0
  - spreed: 15.0.6
  - support: 1.8.0
  - survey_client: 1.13.0
  - systemtags: 1.15.0
  - tasks: 0.15.0
  - text: 3.6.0
  - theming: 2.0.1
  - twofactor_backupcodes: 1.14.0
  - user_ldap: 1.15.0
  - user_status: 1.5.0
  - viewer: 1.9.0
  - weather_status: 1.5.0
  - workflowengine: 2.7.0
Disabled:
  - accessibility
  - activity: 2.15.0
  - admin_audit
  - bruteforcesettings
  - deck: 1.8.5
  - encryption
  - files_videoplayer
  - groupfolders: 13.1.3
  - integration_whiteboard: 0.0.14
  - richdocuments: 7.1.4
  - shifts: 1.8.6
  - suspicious_login
  - talked: 0.5.0
  - twofactor_totp
  - updatenotification: 1.12.0

Nextcloud Signing status

No response

Nextcloud Logs

No response

Additional info

No response

Start with the occ user:delete testuser entry point and trace the user-removal path for the listed tables: oc_addressbookchanges, oc_jobs, oc_storages, and oc_mail_tags. Reproduce the deletion with a test user, determine which remaining rows are expected, and verify that the agreed cleanup behavior is consistent across the tables.