Marketing tool Klaviyo leaked customer passwords to ad platforms for 21 months

A broken sign-up form in Klaviyo, a marketing platform with 205,000 paying customers, sent new customers' emails, passwords, phone numbers, and company details to ad sites including Facebook, Google, and X for at least 21 months, per researcher Sam Jadali. Klaviyo fixed the problem but hasn't publicly disclosed it. It says fewer than 200 people were affected, based on its current logs.