{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-20074", "assignerOrgId": "d1c1063e-7a18-46af-9102-31f8928bc633", "state": "PUBLISHED", "assignerShortName": "cisco", "dateReserved": "2025-10-08T11:59:15.362Z", "datePublished": "2026-03-11T16:31:14.712Z", "dateUpdated": "2026-03-11T17:20:21.640Z"}, "containers": {"cna": {"title": "Cisco IOS XR Software Multi-Instance Intermediate System-to-Intermediate System Denial of Service Vulnerability", "metrics": [{"format": "cvssV3_1", "cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H", "baseScore": 7.4, "baseSeverity": "HIGH", "attackVector": "ADJACENT_NETWORK", "attackComplexity": "LOW", "privilegesRequired": "NONE", "userInteraction": "NONE", "scope": "CHANGED", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "availabilityImpact": "HIGH"}}], "descriptions": [{"lang": "en", "value": "A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) multi-instance routing feature of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause the IS-IS process to restart unexpectedly.\r\n\r\nThis vulnerability is due to insufficient input validation of ingress IS-IS packets. An attacker could exploit this vulnerability by sending crafted IS-IS packets to an affected device after forming an adjacency. A successful exploit could allow the attacker to cause the IS-IS process to restart unexpectedly, resulting in a temporary loss of connectivity to advertised networks and a denial of service (DoS) condition.\r\nNote: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and must have formed an adjacency.  "}], "references": [{"url": "https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-isis-dos-kDMxpSzK", "name": "cisco-sa-isis-dos-kDMxpSzK"}], "exploits": [{"lang": "en", "value": "The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory."}], "source": {"advisory": "cisco-sa-isis-dos-kDMxpSzK", "discovery": "INTERNAL", "defects": ["CSCwq71827"]}, "problemTypes": [{"descriptions": [{"lang": "en", "description": "Improper Validation of Specified Type of Input", "type": "cwe", "cweId": "CWE-1287"}]}], "affected": [{"vendor": "Cisco", "product": "Cisco IOS XR Software", "versions": [{"version": "7.8.1", "status": "affected"}, {"version": "7.9.1", "status": "affected"}, {"version": "7.10.1", "status": "affected"}, {"version": "7.8.2", "status": "affected"}, {"version": "7.8.22", "status": "affected"}, {"version": "7.9.2", "status": "affected"}, {"version": "7.11.1", "status": "affected"}, {"version": "7.9.21", "status": "affected"}, {"version": "7.10.2", "status": "affected"}, {"version": "24.1.1", "status": "affected"}, {"version": "7.11.2", "status": "affected"}, {"version": "24.2.1", "status": "affected"}, {"version": "24.1.2", "status": "affected"}, {"version": "24.2.11", "status": "affected"}, {"version": "24.3.1", "status": "affected"}, {"version": "24.4.1", "status": "affected"}, {"version": "24.2.2", "status": "affected"}, {"version": "7.8.23", "status": "affected"}, {"version": "7.11.21", "status": "affected"}, {"version": "24.2.20", "status": "affected"}, {"version": "24.3.2", "status": "affected"}, {"version": "24.4.10", "status": "affected"}, {"version": "25.1.1", "status": "affected"}, {"version": "24.4.2", "status": "affected"}, {"version": "24.3.20", "status": "affected"}, {"version": "24.4.15", "status": "affected"}, {"version": "25.2.1", "status": "affected"}, {"version": "25.1.2", "status": "affected"}, {"version": "24.3.30", "status": "affected"}, {"version": "24.4.30", "status": "affected"}, {"version": "24.2.21", "status": "affected"}, {"version": "25.2.15", "status": "affected"}], "defaultStatus": "unknown"}], "providerMetadata": {"orgId": "d1c1063e-7a18-46af-9102-31f8928bc633", "shortName": "cisco", "dateUpdated": "2026-03-11T16:31:14.712Z"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-20074", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "partial"}], "version": "2.0.3", "timestamp": "2026-03-11T17:04:46.266844Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-03-11T17:20:21.640Z"}}]}}

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