Electrum wallet releases version 4.8.3 to fix a critical security vulnerability; users urged to upgrade immediately.
Tech & Launches ·
Electrum wallet released version 4.8.3 on October 24, 2026, to address a critical security vulnerability affecting all prior versions. The flaw allowed malicious servers to substitute legitimate transactions with crafted replacements bearing attacker addresses, which the light client failed to validate before displaying them—a risk that escalated when users manually raised transaction fees. Two incidents were documented: one user found their broadcasted transaction replaced in wallet history, and another lost funds after fee-bumping a zero-fee transaction injected by an attacker. The patch verifies signatures for mempool transactions before storing them locally, and all users are urged to upgrade immediately.