[Bug]: MariaDB - "Too many connection" after NC33 upgrade

⚠️ 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 OR Nextcloud Community Forum (I've searched it).
• Nextcloud Server is up to date. See Maintenance and Release Schedule for supported versions.
• I agree to follow Nextcloud's Code of Conduct.

Bug description

After upgrading my Linuxserver docker image with NC33 I get the following error "Exception
Failed to connect to the database: An exception occurred in the driver: SQLSTATE[HY000] [1040] Too many connections" - MariaDB 11.4.8 in its own docker container PHP 8.4.16 bundled in NC docker image.

Usablly it comes when browsing the pics in the photos app. CPU goes to 100% and memory increases to 3GB

Steps to reproduce

1. Usablly it comes when browsing the pics in the photos app. CPU goes to 100% and memory increases to 3GB
2. Filter the pics in a certain timeframe e.g. last month

Expected behavior

Browsing the pics like with NC32. There was the "Too many connection" error not showing

Nextcloud Server version

33

Operating system

Other

PHP engine version

PHP 8.4

Web server

Nginx

Database engine version

MariaDB

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

Upgraded to a MAJOR version (ex. 31 to 32)

Are you using the Nextcloud Server Encryption module?

Encryption is Disabled

What user-backends are you using?

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

Configuration report

{
    "system": {
        "memcache.local": "\\OC\\Memcache\\APCu",
        "datadirectory": "***REMOVED SENSITIVE VALUE***",
        "instanceid": "***REMOVED SENSITIVE VALUE***",
        "passwordsalt": "***REMOVED SENSITIVE VALUE***",
        "secret": "***REMOVED SENSITIVE VALUE***",
        "trusted_domains": [
            "192.168.1.204",
            "nextcloud.walzer.me"
        ],
        "dbtype": "mysql",
        "version": "33.0.0.16",
        "trusted_proxies": "***REMOVED SENSITIVE VALUE***",
        "overwrite.cli.url": "https:\/\/nextcloud.walzer.me",
        "overwritehost": "nextcloud.walzer.me",
        "overwriteprotocol": "https",
        "dbname": "***REMOVED SENSITIVE VALUE***",
        "dbhost": "***REMOVED SENSITIVE VALUE***",
        "dbport": "",
        "dbtableprefix": "oc_",
        "mysql.utf8mb4": true,
        "dbuser": "***REMOVED SENSITIVE VALUE***",
        "dbpassword": "***REMOVED SENSITIVE VALUE***",
        "installed": true,
        "maintenance": false,
        "maintenance_window_start": 9,
        "theme": "",
        "loglevel": 2,
        "updater.release.channel": "stable",
        "mail_from_address": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpmode": "smtp",
        "mail_sendmailmode": "smtp",
        "mail_domain": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpauthtype": "LOGIN",
        "mail_smtpauth": 1,
        "mail_smtphost": "***REMOVED SENSITIVE VALUE***",
        "mail_smtpport": "587",
        "mail_smtpname": "***REMOVED SENSITIVE VALUE***",
        "mail_smtppassword": "***REMOVED SENSITIVE VALUE***",
        "default_language": "de",
        "default_locale": "de_AT",
        "default_phone_region": "AT",
        "app_install_overwrite": {
            "0": "files_mindmap",
            "1": "richdocuments",
            "3": "files_trackdownloads",
            "4": "files_antivirus",
            "5": "fulltextsearch",
            "6": "fulltextsearch_elasticsearch",
            "7": "files_fulltextsearch",
            "8": "geoblocker"
        },
        "0": {
            "preview_max_x": "2048",
            "preview_max_y": "2048",
            "jpeg_quality": "60"
        },
        "filelocking.enabled": "true",
        "memcache.locking": "\\OC\\Memcache\\APCu",
        "upgrade.disable-web": true,
        "forbidden_filename_basenames": [
            "con",
            "prn",
            "aux",
            "nul",
            "com0",
            "com1",
            "com2",
            "com3",
            "com4",
            "com5",
            "com6",
            "com7",
            "com8",
            "com9",
            "com\u00b9",
            "com\u00b2",
            "com\u00b3",
            "lpt0",
            "lpt1",
            "lpt2",
            "lpt3",
            "lpt4",
            "lpt5",
            "lpt6",
            "lpt7",
            "lpt8",
            "lpt9",
            "lpt\u00b9",
            "lpt\u00b2",
            "lpt\u00b3"
        ],
        "forbidden_filename_characters": [
            "<",
            ">",
            ":",
            "\"",
            "|",
            "?",
            "*",
            "\\",
            "\/"
        ],
        "forbidden_filename_extensions": [
            " ",
            ".",
            ".filepart",
            ".part"
        ]
    }
}

List of activated Apps

Enabled:
  - activity: 6.0.0-dev.0
  - app_api: 33.0.0
  - bruteforcesettings: 6.0.0-dev.0
  - circles: 33.0.0
  - cloud_federation_api: 1.17.0
  - comments: 1.23.0
  - contactsinteraction: 1.14.1
  - dashboard: 7.13.0
  - dav: 1.36.0
  - federatedfilesharing: 1.23.0
  - federation: 1.23.0
  - files: 2.5.0
  - files_antivirus: 6.1.0
  - files_automatedtagging: 4.0.0
  - files_downloadlimit: 5.1.0-dev.0
  - files_external: 1.25.1
  - files_fulltextsearch: 33.0.0
  - files_pdfviewer: 6.0.0-dev.0
  - files_reminders: 1.6.0
  - files_retention: 4.0.0
  - files_sharing: 1.25.2
  - files_trashbin: 1.23.0
  - files_versions: 1.26.0
  - firstrunwizard: 6.0.0-dev.0
  - fulltextsearch: 33.0.0
  - fulltextsearch_elasticsearch: 33.0.0
  - geoblocker: 0.5.19
  - groupfolders: 21.0.5
  - logreader: 6.0.0
  - lookup_server_connector: 1.21.0
  - nextcloud_announcements: 5.0.0
  - notes: 4.13.0
  - notifications: 6.0.0
  - oauth2: 1.21.0
  - password_policy: 5.0.0-dev.0
  - photos: 6.0.0-dev.0
  - previewgenerator: 5.12.1
  - privacy: 5.0.0-dev.0
  - profile: 1.2.0
  - provisioning_api: 1.23.0
  - recognize: 11.0.1
  - recommendations: 6.0.0-dev.0
  - related_resources: 4.0.0-dev.0
  - richdocuments: 10.1.0
  - serverinfo: 5.0.0-dev.0
  - settings: 1.16.0
  - sharebymail: 1.23.0
  - support: 5.0.0
  - survey_client: 5.0.0-dev.0
  - suspicious_login: 11.0.0-dev.0
  - systemtags: 1.23.0
  - text: 7.0.0-dev.3
  - theming: 2.8.0
  - twofactor_backupcodes: 1.22.0
  - twofactor_totp: 15.0.0-dev.0
  - user_status: 1.13.0
  - viewer: 6.0.0-dev.0
  - weather_status: 1.13.0
  - webhook_listeners: 1.5.0
  - whiteboard: 1.5.6
  - workflowengine: 2.15.0
Disabled:
  - admin_audit: 1.23.0
  - encryption: 2.21.0
  - extract: 1.3.6 (installed 1.3.6)
  - files_rightclick: 1.6.0 (installed 1.6.0)
  - ransomware_protection: 1.14.0 (installed 1.14.0)
  - twofactor_nextcloud_notification: 7.0.0
  - updatenotification: 1.23.0 (installed 1.17.0)
  - user_ldap: 1.24.0
  - user_usage_report: 3.0.0 (installed 3.0.0)

Nextcloud Signing status

No errors have been found.

Nextcloud Logs

Level | Anwendung | Nachricht | Zeit | Eingabeaktionen protokollieren
-- | -- | -- | -- | --
Fehler | webdav | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 20.02.2026, 00:10:14 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 20.02.2026, 00:05:11 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 23:50:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 23:35:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 23:20:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 23:05:12 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 22:50:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 22:35:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 22:20:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 22:05:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 21:50:11 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 21:35:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 21:20:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 21:05:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 20:50:11 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 20:35:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 20:20:01 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 20:05:02 |  
Fehler | core | ErrorCall to undefined method OC\DB\QueryBuilder\QueryBuilder::execute() | 19.02.2026, 19:50:12 |  

Additional info

No response

No source file or test is named. Start by reproducing the failure while browsing and filtering photos, then inspect the repeated core and webdav QueryBuilder::execute() log entries and compare behavior with NC32. Done means the Photos browsing workflow no longer exhausts MariaDB connections after the NC33 upgrade and the regression is covered by an appropriate test.