2025 Klarna — cache configuration data exposure
Data compromised
Names, dates of birth, addresses, ZIP codes, cities, states
Technical writeup
Klarna confirmed customer data leak Nov 2025. Incorrect cache configuration caused credit application form to serve cached data from other users—names, DOB, addresses, ZIP, city, state. 'Rare scenario' rather than system-wide breach; actual impact ~99% lower than initial 288K theoretical estimate. Company declined to disclose exact number affected.
Root cause
Incorrect cache configuration; improper cache key handling