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CVE-2024-20406

Cisco IOS XR - IS-IS Protocol

Cisco CVSS 7.4 Updated March 16, 2026

Executive Risk Summary

"A vulnerability in the segment routing feature for the Intermediate System-to-Intermediate System (IS-IS) protocol of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation of ingress IS-IS packets and can be exploited by sending specific IS-IS packets to an affected device after forming an adjacency."

Operational Audit Arsenal

Target Type Firmware Image
Target Asset IS-IS Protocol
Standard Path Global Firmware

Manual Verification Required

This is a non-Windows asset (Cisco). Use the target asset details and official path provided above to verify your current version against the official vendor advisories listed below.

Patch Impact Forecast

Reboot Required Likely

Network disruption possible due to DoS condition

Internal Work Notes

CVE-2024-20406: Potential DoS vulnerability in Cisco IOS XR IS-IS protocol, recommend verification of device configuration and software version

Technical Intelligence & Operational Utilities • Delivered Weekly

Intelligence Sources

Related Cisco Threats

Data compiled from NVD, MSRC, and CISA KEV Catalog. Intelligence synthesized via AI. Scripts provided for diagnostic purposes under MIT License.