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VULNERABILITIES

CVE-2026-120596 Details

ANALYZED

This CVE record has been analyzed and enriched by NVDAPI.com as an independent party.

Description

A remotely exploitable denial-of-service vulnerability exists in the TCP options parser of the Nut/Net TCP/IP stack included in Nut/OS, developed by Ethernut/Egnite. Nut/OS releases up to version 5.1 are affected. An unauthenticated attacker can send a single TCP segment containing an unknown TCP option with a length byte of zero to any open TCP port on a vulnerable device. When processed, this malformed option triggers an infinite loop in the function NutTcpInputOptions, permanently blocking the TCP processing thread and rendering all TCP-based services unresponsive until the device is rebooted.

Metrics

CVSS 3.x Severity and Vector Strings:

NDDVolerionCVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CNA: CISA-ADPCVSS-B:7.5 HIGHVector:CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References to Advisories, Solutions, and Tools

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URLSource(s)Tag(s)
https://www.ethernut.de/en/download/index.html [email protected]ProductVendor

Weakness Enumeration

CWE-IDCWE NameSource
CWE-835Loop with Unreachable Exit Condition ('Infinite Loop')CISA-ADP

Affected Products

ProductVersions
Ethernut Nut/OS
<= 5.1

CPE

  • cpe:2.3:o:ethernut:nut/os:*:*:*:*:*:*:*:*

Remediation

Change History

2 change records found show changes

QUICK INFO

CVE Dictionary Entry:
CVE-2026-120596
NVD Published Date:
Nov 2, 2026
NVD Last Modified:
Nov 2, 2026
Source:
[email protected]
CVE-2026-120596 Details - Not Deferred