Is CVE-2021-1587 actively exploited?

No active exploitation of CVE-2021-1587 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2021-1587 be exploited remotely?

Yes. CVE-2021-1587 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2021-1587?

CVE-2021-1587 has a CVSS score of 8.6 (HIGH).

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HIGH

CVE-2021-1587

CWE-115Published: August 25, 2021· Updated: Jun 17, 2026

8.6

CVSS v3.1

Official Description

A vulnerability in the VXLAN Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software, known as NGOAM, could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of specific packets with a Transparent Interconnection of Lots of Links (TRILL) OAM EtherType. An attacker could exploit this vulnerability by sending crafted packets, including the TRILL OAM EtherType of 0x8902, to a device that is part of a VXLAN Ethernet VPN (EVPN) fabric. A successful exploit could allow the attacker to cause an affected device to experience high CPU usage and consume excessive system resources, which may result in overall control plane instability and cause the affected device to reload. Note: The NGOAM feature is disabled by default.

NVD Source

Technical Analysis

CVE-2021-1587 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.

CVSS v3.1 Vector Breakdown

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges Req.None

User InteractionNone

ScopeChanged

Impact

ConfidentialityNone

IntegrityNone

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Affected Vendors & Products

Cisco63 product(s)

nx-osnexus 3000nexus 3048nexus 31108pc-vnexus 31108tc-vnexus 31128pqnexus 3132c-znexus 3132q-vnexus 3132q-x\/3132q-xlnexus 3164qnexus 3172pq\/pq-xlnexus 3172tq-xl+51

Source: NVD CPE · 63 total CPE entries