Is CVE-2026-20084 actively exploited?

No active exploitation of CVE-2026-20084 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-20084 be exploited remotely?

Yes. CVE-2026-20084 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-20084?

CVE-2026-20084 has a CVSS score of 8.6 (HIGH).

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HIGH

CVE-2026-20084

CWE-400Published: March 25, 2026· Updated: Mar 26, 2026

8.6

CVSS v3.1

EPSS:0.11%probability of exploitation in 30 daysPercentile:28.8th

Official 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.

NVD Source

Technical Analysis

CVE-2026-20084 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 8.6.

The vulnerability has a "Changed" scope, meaning successful exploitation can impact components beyond the vulnerable component itself — such as the host operating system or adjacent services.