CVE-2026-20084

A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause BOOTP packets to be forwarded between VLANs, resulting in a denial of ser

Severity
High 8.6
CVSS 3.1
Exploited
Not listed
EPSS
0.004
28.0th percentile
Discovered by
Third party
Published by the vendor
Published
Mar 25, 2026
Assigned by cisco

Description

A vulnerability in the DHCP snooping feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause BOOTP packets to be forwarded between VLANs, resulting in a denial of service (DoS) condition. This vulnerability is due to improper handling of BOOTP packets on Cisco Catalyst 9000 Series Switches. An attacker could exploit this vulnerability by sending BOOTP request packets to an affected device. A successful exploit could allow an attacker to forward BOOTP packets from one VLAN to another, resulting in BOOTP VLAN leakage and potentially leading to high CPU utilization. This makes the device unreachable (either through console or remote management) and unable to forward traffic, resulting in a DoS condition. Note: This vulnerability can be exploited with either unicast or broadcast BOOTP packets. There are workarounds that address this vulnerability.

Weakness: CWE-400

Affected products

Vendor Product Category Matched by
Cisco Cisco IOS XE Software Routing & Switching cna-assigner
Vendor-reported affected versions (1)
  • Cisco · Cisco IOS XE Software