CVE-2026-120596
Summary
| CVE | CVE-2026-120596 |
|---|---|
| State | PUBLISHED |
| Assigner | certcc |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-02 17:17:40 UTC |
| Updated | 2026-11-02 19:35:33 UTC |
| 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. |
Risk And Classification
Primary CVSS: v3.1 7.5 HIGH from ADP
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Problem Types: CWE-835 | CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop') | CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer | CWE-20 Improper Input Validation | CWE-835 CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | ADP | DECLARED | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | Secondary | 7.5 | HIGH | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Ethernut Egnite GmbH | Nut/Net TCP/IP Stack | affected Nut/OS 5.1 | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.ethernut.de/en/download/index.html | [email protected] | www.ethernut.de | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.