Hacking News
Electrum Fixes Bitcoin Wallet Flaw Exploited by Malicious Servers
Electrum, a Bitcoin wallet, disclosed a high-severity vulnerability affecting all versions before 4.8.3. The vulnerability, disclosed on October 24, 2026, enabled malicious servers to mislead users into authorizing fraudulent transactions during a fee increase. Developers confirmed at least one instance of lost Bitcoin (BTC) out of two reported incidents. The vulnerability allowed a malicious server to use a normal outgoing payment as an opportunity for theft. Version 4.8.3, released on October 24, prevented signature validation of inputs that incur spending coins in the wallet before an unconfirmed transaction is added to local history.