NetSight
critical9.3

CVE-2026-117603

Electrum before 4.7.2 Nostr Wallet Connect Plugin Daily Spending Limit Bypass

Impact

Electrum before 4.7.2 contains a spending limit bypass vulnerability in the Nostr Wallet Connect plugin that allows malicious NWC clients to exceed daily_limit_sat by exploiting non-atomic budget checks and millisatoshi truncation. Attackers can send concurrent pay_invoice requests that pass budget_allows_spend() before add_to_budget() runs, or repeatedly pay msat amounts that are floored to whole satoshis, to drain funds beyond the limit.

Affected products

VendorProductAffected versions
SpesmiloElectrum
before 4.7.2

Weakness classification

References