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CVE-2026-117601

7.5, high

Electrum before 4.8.3 fails to verify signatures of wallet-owned inputs in unconfirmed mempool transactions, allowing malicious servers…

NVD (opens in a new tab) CVE.org (opens in a new tab)
CVSS
7.5, high high CVSS v3.1
EPSS, next 30 days
n/a
Exploitation
No public evidence
Published
27 Oct 2026yesterday

Description

Electrum before 4.8.3 fails to verify signatures of wallet-owned inputs in unconfirmed mempool transactions, allowing malicious servers to replace a just-broadcast transaction with a conflicting one. Attackers can swallow the user's transaction and display an invalid zero-fee copy paying an attacker address, tricking users into RBF fee-bumping and signing it.

Details

Vendor
Spesmilo
Product
electrum
Weakness
CWE-347 (opens in a new tab)
Status
Awaiting analysis
Updated
27 Oct 2026
Assigner
disclosure@vulncheck.com

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

References 3

Patches and fixes 1

Advisories 1

Other references 1

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

Other Spesmilo CVEs

Every Spesmilo CVE we hold

Same vendor in what we hold, not a known link between the flaws.

  • CVE-2026-117602 Electrum 4.6.0 before 4.7.2 contains an authorization bypass in the external plugin loader, which executes a plugin's __init__.py module… 8.4, high

Beyond this page

Is CVE-2026-117601 in your network?

This page tells you how dangerous CVE-2026-117601 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2026-117601 comes with the devices to patch.

    Learn more about EXYS7600 OCELOT

  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 28 Oct 2026, not the live upstream state.