CVE-2025-20340
Cisco IOS XR Address Resolution Protocol Broadcast Storm Vulnerability
Description
A vulnerability in the Address Resolution Protocol (ARP) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a broadcast storm, leading to a denial of service (DoS) condition on an affected device. This vulnerability is due to how Cisco IOS XR Software processes a high, sustained rate of ARP traffic hitting the management interface. Under certain conditions, an attacker could exploit this vulnerability by sending an excessive amount of traffic to the management interface of an affected device, overwhelming its ARP processing capabilities. A successful exploit could result in degraded device performance, loss of management connectivity, and complete unresponsiveness of the system, leading to a DoS condition.
Weakness: CWE-400
Affected products
| Vendor | Product | Category | Matched by |
|---|---|---|---|
| Cisco | Cisco IOS XR Software | Routing & Switching | cna-assigner |
Vendor-reported products (1)
- Cisco · Cisco IOS XR Software
Vendor advisory
cisco-sa-iosxr-arp-storm-EjUU55yM
Cisco IOS XR ARP Broadcast Storm Denial of Service Vulnerability
Cisco’s rating: High (advisory CVSS 7.4) · Published Sep 10, 2025
Bug ID: CSCwm86399
The vendor’s rating applies to the whole advisory and can differ from this CVE’s own CVSS severity. Where this comes from