{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-120596", "assignerOrgId": "37e5125f-f79b-445b-8fad-9564f167944b", "state": "PUBLISHED", "assignerShortName": "certcc", "dateReserved": "2026-11-02T16:58:49.331Z", "datePublished": "2026-11-02T17:04:18.611Z", "dateUpdated": "2026-11-02T17:17:35.066Z"}, "containers": {"cna": {"title": "CVE-2026-120596", "descriptions": [{"lang": "en", "value": "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."}], "source": {"discovery": "UNKNOWN"}, "affected": [{"vendor": "Ethernut / egnite GmbH", "product": "Nut/Net TCP/IP Stack", "versions": [{"status": "affected", "version": "Nut/OS 5.1"}]}], "problemTypes": [{"descriptions": [{"lang": "en", "description": "CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"}]}, {"descriptions": [{"lang": "en", "description": "CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer"}]}, {"descriptions": [{"lang": "en", "description": "CWE-20 Improper Input Validation"}]}], "references": [{"url": "https://www.ethernut.de/en/download/index.html"}], "x_generator": {"engine": "VINCE 3.0.52", "env": "prod", "origin": "https://cveawg.mitre.org/api/cve/CVE-2026-120596"}, "providerMetadata": {"orgId": "37e5125f-f79b-445b-8fad-9564f167944b", "shortName": "certcc", "dateUpdated": "2026-11-02T17:04:18.611Z"}}, "adp": [{"problemTypes": [{"descriptions": [{"type": "CWE", "cweId": "CWE-835", "lang": "en", "description": "CWE-835 Loop with Unreachable Exit Condition ('Infinite Loop')"}]}], "metrics": [{"cvssV3_1": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}}, {"other": {"type": "ssvc", "content": {"timestamp": "2026-11-02T17:17:32.319063Z", "id": "CVE-2026-120596", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "partial"}], "role": "CISA Coordinator", "version": "2.0.3"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-11-02T17:17:35.066Z"}}]}}