{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-20051", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-20051", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-02-25T16:14:33.859Z", "updatedAt": "2026-02-25T19:05:49.650Z", "importedAt": "2026-10-24T01:57:55.771Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "Cisco Nexus 3600-R and 9500-R Series Switching Platforms Layer 2 Loop Denial of Service Vulnerability", "summary": "A vulnerability with the Ethernet VPN (EVPN) Layer 2 ingress packet processing of Cisco Nexus 3600 Platform Switches and Cisco Nexus 9500-R Series Switching Platforms could allow an unauthenticated, adjacent attacker to trigger a Layer 2 traffic loop.\r\n\r\nThis vulnerability is due to a logic error when processing a crafted Layer 2 ingress frame. An attacker could exploit this vulnerability by sending a stream of crafted Ethernet frames through the targeted device. A successful exploit could allow the attacker to cause a Layer 2 Virtual eXtensible LAN (VxLAN) traffic loop, which, in turn, could result in a denial of service (DoS) condition. This Layer 2 loop could oversubscribe the bandwidth on network interfaces, which would result in all data plane traffic being dropped. To exploit this vulnerability, the attacker must be Layer 2-adjacent to the affected device.\r\nNote: To stop active exploitation of this vulnerability, manual intervention is required to both stop the crafted traffic and flap all involved network interfaces. For additional assistance if a Layer 2 loop that is related to this vulnerability is suspected, contact the Cisco Technical Assistance Center (TAC) or the proper support provider. ", "affected": [ { "vendor": "Cisco", "product": "Cisco NX-OS Software", "defaultStatus": "unknown", "versions": [ { "version": "9.2(3)", "status": "affected" }, { "version": "9.2(2v)", "status": "affected" }, { "version": "9.2(1)", "status": "affected" }, { "version": "9.2(2t)", "status": "affected" }, { "version": "9.2(3y)", "status": "affected" }, { "version": "9.3(2)", "status": "affected" }, { "version": "9.2(4)", "status": "affected" }, { "version": "9.3(1)", "status": "affected" }, { "version": "9.3(1z)", "status": "affected" }, { "version": "9.2(2)", "status": "affected" }, { "version": "9.3(3)", "status": "affected" }, { "version": "9.3(4)", "status": "affected" }, { "version": "9.3(5)", "status": "affected" }, { "version": "9.3(6)", "status": "affected" }, { "version": "9.3(5w)", "status": "affected" }, { "version": "9.3(7)", "status": "affected" }, { "version": "9.3(7k)", "status": "affected" }, { "version": "10.2(1)", "status": "affected" }, { "version": "9.3(7a)", "status": "affected" }, { "version": "9.3(8)", "status": "affected" }, { "version": "10.2(1q)", "status": "affected" }, { "version": "10.2(2)", "status": "affected" }, { "version": "9.3(9)", "status": "affected" }, { "version": "10.2(3)", "status": "affected" }, { "version": "10.2(3t)", "status": "affected" }, { "version": "9.3(10)", "status": "affected" }, { "version": "10.2(2a)", "status": "affected" }, { "version": "10.3(1)", "status": "affected" }, { "version": "10.2(4)", "status": "affected" }, { "version": "10.3(2)", "status": "affected" }, { "version": "9.3(11)", "status": "affected" }, { "version": "10.3(3)", "status": "affected" }, { "version": "10.2(5)", "status": "affected" }, { "version": "9.3(12)", "status": "affected" }, { "version": "10.2(3v)", "status": "affected" }, { "version": "10.4(1)", "status": "affected" }, { "version": "10.2(6)", "status": "affected" }, { "version": "10.3(3w)", "status": "affected" }, { "version": "10.3(3o)", "status": "affected" }, { "version": "10.3(4)", "status": "affected" }, { "version": "10.3(3p)", "status": "affected" }, { "version": "10.3(4a)", "status": "affected" }, { "version": "10.4(2)", "status": "affected" }, { "version": "10.3(3q)", "status": "affected" }, { "version": "9.3(13)", "status": "affected" }, { "version": "10.3(5)", "status": "affected" }, { "version": "10.2(7)", "status": "affected" }, { "version": "10.4(3)", "status": "affected" }, { "version": "10.3(3x)", "status": "affected" }, { "version": "10.3(4g)", "status": "affected" }, { "version": "10.5(1)", "status": "affected" }, { "version": "10.2(8)", "status": "affected" }, { "version": "10.3(3r)", "status": "affected" }, { "version": "10.3(6)", "status": "affected" }, { "version": "9.3(14)", "status": "affected" }, { "version": "10.4(4)", "status": "affected" }, { "version": "10.3(4h)", "status": "affected" }, { "version": "10.5(2)", "status": "affected" }, { "version": "10.3(7)", "status": "affected" }, { "version": "10.4(5)", "status": "affected" }, { "version": "10.5(3)", "status": "affected" }, { "version": "10.2(9)", "status": "affected" }, { "version": "9.3(15)", "status": "affected" }, { "version": "10.4(4g)", "status": "affected" }, { "version": "10.5(4)", "status": "affected" }, { "version": "10.6(1)", "status": "affected" }, { "version": "10.5(3t)", "status": "affected" }, { "version": "10.3(8)", "status": "affected" }, { "version": "10.4(6)", "status": "affected" }, { "version": "10.5(3s)", "status": "affected" }, { "version": "10.5(3e)", "status": "affected" }, { "version": "10.5(3o)", "status": "affected" }, { "version": "9.3(16)", "status": "affected" }, { "version": "10.6(1s)", "status": "affected" }, { "version": "10.5(3p)", "status": "affected" } ] } ] } } }