Aborted connection 5 to db: 'unconnected' user

Hi all,

New install and getting the following error:

```
2025-07-18 15:51:15+10:00 [Note] [Entrypoint]: Entrypoint script for MariaDB Server 1:11.8.2+maria~ubu2404 started.
2025-07-18 15:51:15+10:00 [Warn] [Entrypoint]: /sys/fs/cgroup///memory.pressure not writable, functionality unavailable to MariaDB
2025-07-18 15:51:15+10:00 [Note] [Entrypoint]: Switching to dedicated user 'mysql'
2025-07-18 15:51:15+10:00 [Note] [Entrypoint]: Entrypoint script for MariaDB Server 1:11.8.2+maria~ubu2404 started.
2025-07-18 15:51:15+10:00 [Note] [Entrypoint]: MariaDB upgrade not required
2025-07-18 15:51:15 0 [Note] Starting MariaDB 11.8.2-MariaDB-ubu2404 source revision 8d36cafe4fc700e6e577d5a36650c58707e76b92 server_uid cg2n+cvYia9ajABzuXTw6QJBAQg= as process 1
2025-07-18 15:51:15 0 [Note] InnoDB: Compressed tables use zlib 1.3
2025-07-18 15:51:15 0 [Note] InnoDB: Number of transaction pools: 1
2025-07-18 15:51:15 0 [Note] InnoDB: Using ARMv8 crc32 + pmull instructions
2025-07-18 15:51:15 0 [Note] mariadbd: O_TMPFILE is not supported on /tmp (disabling future attempts)
2025-07-18 15:51:15 0 [Warning] mariadbd: io_uring_queue_init() failed with EPERM: sysctl kernel.io_uring_disabled has the value 2, or 1 and the user of the process is not a member of sysctl kernel.io_uring_group. (see man 2 io_uring_setup).
2025-07-18 15:51:15 0 [Warning] InnoDB: liburing disabled: falling back to innodb_use_native_aio=OFF
2025-07-18 15:51:15 0 [Note] InnoDB: innodb_buffer_pool_size_max=128m, innodb_buffer_pool_size=128m
2025-07-18 15:51:15 0 [Note] InnoDB: Completed initialization of buffer pool
2025-07-18 15:51:15 0 [Note] InnoDB: File system buffers for log disabled (block size=4096 bytes)
2025-07-18 15:51:15 0 [Note] InnoDB: End of log at LSN=1292900
2025-07-18 15:51:16 0 [Note] InnoDB: Opened 3 undo tablespaces
2025-07-18 15:51:16 0 [Note] InnoDB: 128 rollback segments in 3 undo tablespaces are active.
2025-07-18 15:51:16 0 [Note] InnoDB: Setting file './ibtmp1' size to 12.000MiB. Physically writing the file full; Please wait ...
2025-07-18 15:51:16 0 [Note] InnoDB: File './ibtmp1' size is now 12.000MiB.
2025-07-18 15:51:16 0 [Note] InnoDB: log sequence number 1292900; transaction id 1050
2025-07-18 15:51:16 0 [Note] InnoDB: Loading buffer pool(s) from /var/lib/mysql/ib_buffer_pool
2025-07-18 15:51:16 0 [Note] Plugin 'FEEDBACK' is disabled.
2025-07-18 15:51:16 0 [Note] Plugin 'wsrep-provider' is disabled.
2025-07-18 15:51:16 0 [Note] InnoDB: Buffer pool(s) load completed at 250718 15:51:16
2025-07-18 15:51:21 0 [Note] Server socket created on IP: '0.0.0.0'.
2025-07-18 15:51:21 0 [Note] Server socket created on IP: '::'.
2025-07-18 15:51:21 0 [Note] mariadbd: Event Scheduler: Loaded 0 events
2025-07-18 15:51:21 0 [Note] mariadbd: ready for connections.
Version: '11.8.2-MariaDB-ubu2404' socket: '/run/mysqld/mysqld.sock' port: 3306 mariadb.org binary distribution
2025-07-18 15:51:41 5 [Warning] Aborted connection 5 to db: 'unconnected' user: 'unauthenticated' host: '172.18.0.4' (This connection closed normally without authentication)
```

Portainer Stack:

```
services:
### Wallabag ###
wallabag:
image: wallabag/wallabag:latest
environment:
- MYSQL_ROOT_PASSWORD=wallaroot
- SYMFONY__ENV__DATABASE_DRIVER=pdo_mysql
- SYMFONY__ENV__DATABASE_HOST=db
- SYMFONY__ENV__DATABASE_PORT=3306
- SYMFONY__ENV__DATABASE_NAME=wallabag
- SYMFONY__ENV__DATABASE_USER=$DATABASE_USERNAME
- SYMFONY__ENV__DATABASE_PASSWORD=$DATABASE_PASSWORD
- SYMFONY__ENV__DATABASE_CHARSET=utf8mb4
- SYMFONY__ENV__DATABASE_TABLE_PREFIX="wallabag_"
- SYMFONY__ENV__MAILER_DSN=$SMTP_MAILER_DSN
- SYMFONY__ENV__FROM_EMAIL=$SMTP_FROM
- SYMFONY__ENV__TWOFACTOR_SENDER=$SMTP_FROM
- SYMFONY__ENV__DOMAIN_NAME=$SMTP_DOMAIN
- SYMFONY__ENV__SERVER_NAME="Greg's Wallabag Server"
- SYMFONY__ENV__FOSUSER_REGISTRATION=false
- PUID=1002
- PGID=1002
- TZ=Australia/Sydney

ports:
- '6080:80'
volumes:
- /appdata/wallabag/images:/var/www/wallabag/web/assets/images
healthcheck:
test: ["CMD", "wget" ,"--no-verbose", "--tries=1", "--spider", "http://127.0.0.1"]
interval: 1m
timeout: 3s

networks:
- wallabag
restart: unless-stopped
depends_on:
db:
condition: service_healthy
redis:
condition: service_healthy
### Mariadb ###
db:
image: mariadb:latest
volumes:
- /appdata/wallabag/data:/var/lib/mysql
environment:
- MYSQL_ROOT_PASSWORD=$MYSQL_PASSWORD
- PUID=1002
- PGID=1002
- TZ=Australia/Sydney
healthcheck:
test: ["CMD", "/usr/local/bin/healthcheck.sh", "--innodb_initialized"]
start_period: 5s
interval: 20s
timeout: 3s
retries: 5
networks:
- wallabag
restart: unless-stopped

### Redis ###
redis:
image: redis:alpine
environment:
- PUID=1002
- PGID=1002
- TZ=Australia/Sydney
healthcheck:
test: ["CMD", "redis-cli", "ping"]
interval: 20s
timeout: 3s
volumes:
- /appdata/wallabag/redis/data:/data
networks:
- wallabag
restart: unless-stopped

networks:
wallabag:
```

The URL shows the following:


Any ideas what I have done incorrectly would be appreciated.

TIA

Start by reproducing the supplied Portainer stack and inspecting the MariaDB and Wallabag container logs around startup and authentication. Compare the environment-variable values and service connectivity shown in the compose configuration; done means identifying the cause of the connection warning and documenting a verified configuration or reproduction.

Written by the indexing model from the issue text.