Polkadot Warns Fearless Wallet Extension Leaked Private Keys Since February 2025

Polkadot has issued an urgent security warning after investigators discovered that multiple versions of the Fearless Wallet browser extension secretly transmitted users' private keys to an attacker-controlled server for periods dating back to February 2025. The Polkadot Community Foundation disclosed the vulnerability on October 21, 2026, identifying versions 3.0.1, 3.0.3, 3.0.4 and 3.0.5 as affected. Eight users have reported unauthorized transactions potentially linked to the incident, involving 17,286 DOT. Anyone who used the extension since February 2025 has been instructed to abandon their existing wallet keys, generate new credentials through a different wallet application and transfer their remaining assets immediately.