Vulnerability · Published Oct 27, 2026 · Assigned by VulnCheck

CVE-2026-117603Electrum before 4.7.2 Nostr Wallet Connect Plugin Daily Spending Limit Bypass

Medium 4.3

In plain English

A medium-severity security flaw in electrum from spesmilo. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.2% (higher than 9% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)4.3Medium

Exploit odds (30 days)0.2%top 90.8% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:14	electrum	4.8.1+dfsg-1	DEBIAN-CVE-2026-117603

Affected products (as reported)

Vendor	Product	Versions
spesmilo	electrum	0 – before 4.7.2

Weakness: CWE-367 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

GitHub Security Advisory (GHSA-q7m2-785w-r585) vendor-advisory
Patch Commit patch
Patch Commit patch
VulnCheck Advisory: Electrum before 4.7.2 Nostr Wallet Connect Plugin Daily Spending Limit Bypass third-party-advisory