Private data and passwords of high-ranking US security politicians found online by journalists of German news outlet

EDIT: Since I've posted this, an English language version of the article has been published. Here is the link. @Mods: please let me know if I should replace it in the in the URL field as well, I'm going to leave it as is for know,

Article both in German and behind a paywall. I've translated the most relevant parts:

Donald Trump's most important security advisors discussed a military strike via signal chat. Research by [the German magazine] SPIEGEL now shows that the problem is even bigger. [...] Private contact details of US President Donald Trump's most important security advisors are available on the internet. Research by SPIEGEL revealed mobile numbers, email addresses and, in some cases, passwords.

For the research, information from commercial personal search engines and customer data published online was used. National Security Advisor Mike Waltz, US Intelligence Coordinator Tulsi Gabbard and Secretary of Defense Pete Hegseth are demonstrably affected by the leaks.

Most of the publicly accessible numbers and email addresses are probably still being used by those affected. Some of them are linked to profiles on Instagram and LinkedIn, among others. They were used to create Dropbox accounts and profiles in apps that track running data. There are WhatsApp profiles for the respective phone numbers, and in some cases even Signal accounts. [...] It is therefore conceivable that foreign agents were reading along when Gabbard, Waltz and Hegseth discussed a military strike in a signals chat with others.