---
title: "CVE-2026-117601: Electrum - Authentication Bypass"
description: "Electrum < 4.8.3 contains a transaction signature verification flaw caused by failure to verify wallet-owned inputs in unconfirmed mempool transactions, letting malicious servers replace broadcast transactions, exploit requires malicious server interaction."
url: https://panop.io/threat-heartbeat/CVE-2026-117601/
---

# CVE-2026-117601 Electrum - Authentication Bypass

Electrum < 4.8.3 contains a transaction signature verification flaw caused by failure to verify wallet-owned inputs in unconfirmed mempool transactions, letting malicious servers replace broadcast transactions, exploit requires malicious server interaction.

CVSS base score 7.5 /10

High

CISA KEV

Exploited in the wild

Public exploit

None known

EPSS

0.18% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-117601)

## Details

Type

Authentication Bypass

Impact

Data Tampering

CVSS vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H

Published

27 October 2026

Updated

29 October 2026

Weakness

[CWE-347](https://cwe.mitre.org/data/definitions/347.html)

## Vendor fix

Upgrade to version 4.8.3 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-117601](https://nvd.nist.gov/vuln/detail/CVE-2026-117601)
- [https://github.com/spesmilo/electrum/security/advisories/GHSA-6jp4-8v48-cc5v](https://github.com/spesmilo/electrum/security/advisories/GHSA-6jp4-8v48-cc5v)
- [https://github.com/spesmilo/electrum/commit/90fe30822561e515a9d2d6e5a352cc07780999eb](https://github.com/spesmilo/electrum/commit/90fe30822561e515a9d2d6e5a352cc07780999eb)
- [https://www.vulncheck.com/advisories/electrum-before-4.8.3-missing-signature-verification-of-mempool-transactions](https://www.vulncheck.com/advisories/electrum-before-4.8.3-missing-signature-verification-of-mempool-transactions)

[← All CVEs](https://panop.io/threat-heartbeat/)

## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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