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 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 v3 4.3 MEDIUM

4.3^/10

CVSS v3 : MEDIUM

Vector :

Exploitability : 2.8 / Impact : 1.4

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required LOW

User Interaction NONE

Confidentiality Impact NONE

Integrity Impact LOW

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/spesmilo/electrum/commit/3956bff0684f6060fbe8c823c3ee921928cdcaa5
https://github.com/spesmilo/electrum/commit/5222374046d2a92da371d46c79ce0e61e7e2a42d
https://github.com/spesmilo/electrum/security/advisories/GHSA-q7m2-785w-r585
https://www.vulncheck.com/advisories/electrum-before-4.7.2-nostr-wallet-connect-plugin-daily-spending-limit-bypass

Configurations

No configuration.

History

27 Oct 2026, 14:16

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-10-27 14:16

Updated : 2026-10-27 16:03

NVD link : CVE-2026-117603

Mitre link : CVE-2026-117603

CVE.ORG link : CVE-2026-117603

JSON object : View

Products Affected

No product.

CWE

CWE-367

Time-of-check Time-of-use (TOCTOU) Race Condition

{"id": "CVE-2026-117603", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "disclosure@vulncheck.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 4.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:L/A:N", "integrityImpact": "LOW", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "NONE", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "disclosure@vulncheck.com", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "NOT_DEFINED", "baseScore": 9.3, "Automatable": "NOT_DEFINED", "attackVector": "NETWORK", "baseSeverity": "CRITICAL", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS: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", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "NONE", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "HIGH", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "NONE", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "affected": [{"source": "disclosure@vulncheck.com", "affectedData": [{"vendor": "spesmilo", "product": "electrum", "versions": [{"status": "affected", "version": "0", "lessThan": "4.7.2", "versionType": "semver"}, {"status": "unaffected", "version": "4.7.2", "versionType": "semver"}], "defaultStatus": "unaffected"}]}], "published": "2026-10-27T14:16:40.233", "references": [{"url": "https://github.com/spesmilo/electrum/commit/3956bff0684f6060fbe8c823c3ee921928cdcaa5", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/spesmilo/electrum/commit/5222374046d2a92da371d46c79ce0e61e7e2a42d", "source": "disclosure@vulncheck.com"}, {"url": "https://github.com/spesmilo/electrum/security/advisories/GHSA-q7m2-785w-r585", "source": "disclosure@vulncheck.com"}, {"url": "https://www.vulncheck.com/advisories/electrum-before-4.7.2-nostr-wallet-connect-plugin-daily-spending-limit-bypass", "source": "disclosure@vulncheck.com"}], "vulnStatus": "Awaiting Analysis", "weaknesses": [{"type": "Primary", "source": "disclosure@vulncheck.com", "description": [{"lang": "en", "value": "CWE-367"}]}], "descriptions": [{"lang": "en", "value": "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."}], "lastModified": "2026-10-27T16:03:45.247", "sourceIdentifier": "disclosure@vulncheck.com"}