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.
Advisories

No advisories yet.

Fixes

Solution

No solution given by the vendor.


Workaround

No workaround given by the vendor.

History

Mon, 02 Nov 2026 20:15:00 +0000

Type Values Removed Values Added
Weaknesses CWE-730

Mon, 02 Nov 2026 19:00:00 +0000

Type Values Removed Values Added
Weaknesses CWE-730

Mon, 02 Nov 2026 18:30:00 +0000

Type Values Removed Values Added
Weaknesses CWE-835
Metrics cvssV3_1

{'score': 7.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}


Mon, 02 Nov 2026 17:15:00 +0000

Type Values Removed Values Added
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.
Title CVE-2026-120596
References

Projects

Sign in to view the affected projects.

cve-icon MITRE

Status: PUBLISHED

Assigner: certcc

Published:

Updated: 2026-11-02T17:17:35.066Z

Reserved: 2026-11-02T16:58:49.331Z

Link: CVE-2026-120596

cve-icon Vulnrichment

Updated: 2026-11-02T17:17:28.470Z

cve-icon NVD

Status : Deferred

Published: 2026-11-02T17:17:40.003

Modified: 2026-11-02T19:35:33.347

Link: CVE-2026-120596

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2026-11-02T20:00:04Z

Weaknesses