Data leak at Waltio

On 23 January 2026, Waltio — a French cryptocurrency tax-reporting platform — publicly disclosed a data breach affecting around 50,000 users. The company became aware of the incident on 21 January when an attacker contacted it directly, providing a data sample to prove access and demanding a ransom, which Waltio declined to pay. A copy of the database had reportedly been offered for sale on a hacking forum since late December 2025.

Waltio traced the intrusion to a database management tool, which it removed permanently before conducting further security audits. The company stressed that the compromise did not reach its current production systems and that no data enabling access to users' crypto-assets was exposed.

The exposed information was limited to:

• Email addresses
• 2024 tax-report summaries (aggregated gains/losses and year-end balances)
• Transaction and account counters (in many records, only incomplete report data)

Passwords, exchange API keys, wallet addresses, detailed transaction histories, banking details and identity documents were not affected. The primary risk identified is social engineering — phishing and impersonation of support staff using the leaked contextual data. Waltio filed a criminal complaint for attempted extortion and unauthorized system access, and France's cybercrime division opened an investigation.