CVE-2025-20146 | Cisco IOS XR - Layer 3 Multicast Operational Intel

Executive Risk Summary

"A vulnerability in the Layer 3 multicast feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a line card to reset, resulting in a denial of service (DoS) condition. This vulnerability is due to the incorrect handling of malformed IPv4 multicast packets that are received on line cards where the interface has either an IPv4 access control list (ACL) or a QoS policy applied."

Operational Audit Arsenal

Target Type Firmware Image

Target Asset Cisco IOS XR Software

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

Traffic over the affected line card would be lost while the line card reloads

Internal Work Notes

CVE-2025-20146: Potential DoS condition in Cisco IOS XR Software due to incorrect handling of malformed IPv4 multicast packets, requiring firmware update and potential reboot

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Intelligence Sources

Official Advisoryhttps://blog.apnic.net/2024/09/02/crafting-endless-as-paths-in-bgp/

Official Advisoryhttps://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-multicast-ERMrSvq7

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