9.3 Critical

Electrum before 4.7.2 contains a spending limit bypass vulnerability in the Nostr Wallet Connect plugin that allows malicious NWC clients…

CVE-2026-117603

Electrum before 4.7.2 contains a spending limit bypass vulnerability in the Nostr Wallet Connect plugin that allows malicious NWC clients to exceed dailylimitsat by exploiting non-atomic budget checks and millisatoshi truncation. Attackers can send concurrent payinvoice requests that pass budgetallowsspend() before addtobudget() runs, or repeatedly pay msat amounts that are floored to whole satoshis, to drain funds beyond the limit.

Assessment

CVSS: 9.3 (v4.0)
Severity: Critical
Known exploited: Not listed in CISA KEV
Exploit availability: Nothing found in Exploit-DB, Metasploit, Nuclei or public PoC repositories
Published: 27 October 2026
Last updated: 27 October 2026
Weakness: CWE-367
Assigner: disclosure@vulncheck.com

CVSS vectorCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

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