CVE-2026-117603 Electrum before 4.7.2 Nostr Wallet Connect Plugin Daily Spending Limit Bypass
- Exploited in the wild
- Not known
- Fix
- Available
What is CVE-2026-117603?
CVE-2026-117603 is a critical vulnerability in spesmilo electrum, published on 27 Oct 2026.
Official description
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.
Weakness: CWE-367
Which versions are affected by CVE-2026-117603?
How do I fix CVE-2026-117603?
Upgrade to a fixed version.
Is CVE-2026-117603 being exploited?
There is no known exploitation of CVE-2026-117603 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-117603, GHSA-98mp-7r7x-725c, GHSA-q7m2-785w-r585.