Vulnerability 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.
CVSS Score
MEDIUM
Related Weaknesses (CWE)
References
- https://github.com/spesmilo/electrum/commit/3956bff0684f6060fbe8c823c3ee921928cd
- https://github.com/spesmilo/electrum/commit/5222374046d2a92da371d46c79ce0e61e7e2
- https://github.com/spesmilo/electrum/security/advisories/GHSA-q7m2-785w-r585
- https://www.vulncheck.com/advisories/electrum-before-4.7.2-nostr-wallet-connect-
FAQ
What is CVE-2026-117603?
CVE-2026-117603 is a vulnerability with a CVSS score of 4.3 (MEDIUM). 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 chec...
How severe is CVE-2026-117603?
CVE-2026-117603 has been rated MEDIUM with a CVSS base score of 4.3/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2026-117603?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.