{"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"}}]}}