by Kastro
Paper/Archive/CVE-2026-117603

CVE-2026-117603

spesmilo electrum — Electrum before 4.7.2 Nostr Wallet Connect Plugin Daily Spending Limit Bypass

EPSS 0.2%CVSS 9.3
critical.is priorityof 100
30
CVSS 9.3 (CNA)9.3 / 10 × 3027.9Not in CISA KEV+300.0EPSS percentile 9.1.091 × 201.8No public exploit+100.0SSVC exploitation: unknown+100.0
Description · from the CVE record

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

ProductAffectedFixed inSource
electrum< 4.7.24.7.2CNA

Scores by source

VulnCheck (CNA)9.3CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
VulnCheck (CNA)4.3CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N

References

advisorygithub.com/spesmilo/electrum/security/advisories/GHSA-q7m2-785w-r585patchgithub.com/spesmilo/electrum/commit/5222374046d2a92da371d46c79ce0e61e7e2a42dpatchgithub.com/spesmilo/electrum/commit/3956bff0684f6060fbe8c823c3ee921928cdcaa5writeupvulncheck.com/advisories/electrum-before-4.7.2-nostr-wallet-connect-plugin-daily-spending-limit-bypass