According to CoinMeta, Electrum revealed a high-risk vulnerability prior to version 4.8.3. Malicious servers could induce users, while using the RBF function to increase transaction fees, to send Bitcoin to the attacker's address. Attackers were able to intercept these transactions and replace them with forged ones, generating addresses that matched the last four digits of the intended recipient's address. Electrum has received reports of two incidents, with one user losing funds as a result. This vulnerability has been fixed in version 4.8.3, and Electrum recommends that users update their software immediately and verify their transaction information.