CVE-2026-120596
HIGH
MEDIUM
Priority: 0.03
BB Relevance:
75/100
Published: 2026-11-02
Modified: 2026-11-02
First seen: 2026-11-02
Status: active
Attack Surface
Network
Low Complexity
No Auth
No Interaction
CVSS Vector Breakdown
AV:
Network
AC:
Low
PR:
None
UI:
None
S:
Unchanged
C:
None
I:
None
A:
High
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.
Weakness Classification (1)
Affected Software (2)
| Vendor | Product | Version |
|---|---|---|
| Ethernut / egnite GmbH | Nut/Net TCP/IP Stack | Nut/OS 5.1 |
| Ethernut / egnite GmbH | Nut/Net TCP/IP Stack | Nut/OS 5.1 |