Electrum Users Urged to Update After Fee-Bump Bitcoin Theft

Electrum urged users to update to version 4.8.3 after disclosing a high-risk flaw that let malicious servers redirect Bitcoin (BTC) payments when users tried to raise transaction fees. The flaw affected all versions earlier than 4.8.3. A malicious server could hide a newly broadcast payment and replace it in the wallet’s history with an invalid transaction to an attacker’s address. If a user then raised the fee through Replace-by-Fee, the wallet could sign the substituted transaction. Electrum received two private user reports, dated Oct. 11 and Oct. 18.