cvedb.io
CVE-2026-20074
HIGH · CVSS 7.4
EPSS exploitation probability: 0%
Published 2026-03-11T17:16:55.470 · Last modified 2026-06-17T10:17:01.960

Summary

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. This 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. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device and

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References

This product uses data from the NVD API but is not endorsed or certified by the NVD. Informational only; not professional security advice.