Electrum Releases Wallet Version 4.8.3 Following Exploitation of Fee-Bump Flaw

Electrum has released wallet version 4.8.3 after rogue servers exploited a critical flaw to redirect Bitcoin transactions, resulting in confirmed financial losses for at least one victim. The vulnerability allowed malicious servers to intercept unconfirmed payments and insert zero-fee transactions directing funds to attacker-controlled lookalike addresses. When users attempted to accelerate pending transfers using Replace-by-Fee adjustments, the client unwittingly signed and broadcast the fraudulent replacement transactions. Electrum received initial exploit reports on October 11 and October 18, releasing the patched binaries on October 24 to mandate client-side signature verification for unconfirmed transactions.