CVE-2026-120596 (GCVE-0-2026-120596)
Vulnerability from cvelistv5 – Published: 2026-11-02 17:04 – Updated: 2026-11-02 17:17
VLAI
EPSS
VEX
Title
CVE-2026-120596
Summary
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.
Severity
7.5 (High)
SSVC
Exploitation: none
Automatable: yes
Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-11-02 17:17 UTC
CWE
- 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 - Loop with Unreachable Exit Condition ('Infinite Loop')
Assigner
References
1 reference
Impacted products
1 product
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Ethernut / egnite GmbH | Nut/Net TCP/IP Stack |
Affected:
Nut/OS 5.1
|
guessed |
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Nomenclature
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Browse all ATT&CK techniques and the vulnerabilities related to each.
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