Bitcoin wallet Electrum released version 4.8.3 on October 24 to patch a high-severity flaw affecting earlier versions. Rogue servers could show users a fake, stalled transaction; if a user tried to raise its fee, they could instead sign a new payment to an attacker. Electrum’s advisory says some servers used the attack, and one user reported losing funds on October 18.
The patch checks signatures on wallet-owned inputs before showing unconfirmed transactions, but incoming transactions from external senders remain unverified. Users who connect only to a server they run themselves are not affected.
