Follow the below steps to customize the authentication logo on Wazuh GUI.
Copy your custom image to the path /usr/share/wazuh-dashboard/plugins/wazuh/public/assets
Change the owner to wazuh-dashboard using the command chown wazuh-dashboard:wazuh-dashboard <custom_image>
Edit the file /etc/wazuh-dashboard/opensearch_dashboards.yml and include the below configuration.
opensearch_security.basicauth.login.brandimage: "/plugins/wazuh/assets/<custom_image>"
opensearch_security.basicauth.login.title: "Custom title"
opensearch_security.basicauth.login.subtitle: "Custom subtitile"
The path /plugins/wazuh/assets/<custom_image> translates to usr/share/wazuh-dashboard/plugins/wazuh/public/asset
Restart the wazuh-dashboard: systemctl restart wazuh-dashboard
I will recommend you save your custom image in jpeg, although wazuh supports svg, png, and jpeg.
Please let me know if this helps.
Regards