CVE-2026-117603

Name	CVE-2026-117603
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.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
electrum (PTS)	bookworm	4.3.4+dfsg1-1+deb12u1	vulnerable
	trixie	4.5.8+ds-6	vulnerable
	forky	4.8.1+dfsg-1	fixed
	sid	4.8.3+dfsg-1	fixed

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
electrum	source	(unstable)	4.8.1+dfsg-1

Notes

https://github.com/spesmilo/electrum/security/advisories/GHSA-q7m2-785w-r585
Fixed by: https://github.com/spesmilo/electrum/commit/3956bff0684f6060fbe8c823c3ee921928cdcaa5 (4.8.0)
Fixed by: https://github.com/spesmilo/electrum/commit/5222374046d2a92da371d46c79ce0e61e7e2a42d (4.8.0)