ANP reports (translation):
Foreigners looking for a job in the Netherlands can obtain an assessment of their diploma on the labor market from the organization Nuffic. The application system used by Nuffic has been tested by some sixty software developers in Serbia. This country is not part of the European Union, which means that rather strict rules of confidentiality are applied there for the data. But a program intended to make the data anonymous, did not work there, without knowing why until now.
The leak was discovered on February 9. It then emerged that the data could be viewed by developers since August 11 last year already.
Read more on DataNews. VPNgids.nl also provides coverage of the leak, which they say impacts 18,000 immigrants. Jelle Ursem kindly explained to me that the incident really boiled down to exposure to 60 developers and testers.
h/t, @Chum1ng0