CVE intelligence

CVE-2026-20177

Vulnerability intelligence

Published Aug 19, 2026Sources checked Oct 27, 2026

5.3MEDIUMCVSS out of 10

What this means

Review the available evidence

CVE-2026-20177 and is rated Medium severity with a CVSS score of 5.3. It is not in the current CISA KEV record we collected. That does not prove exploitation has not occurred.

What to do next

Remediation and response

Cisco Security Advisories guidance

Vendor revision: Aug 19, 2026

Vendor remediation details

On August 19, 2026, the Cisco Product Security Incident Response Team (PSIRT) published the following advisories: Cisco Security Advisory CVE ID Security Impact Rating CVSS Base Score Cisco Crosswork Security Hardening Release: August 2026 CVE-2026-20030CVE-2026-20357CVE-2026-20358CVE-2026-20359 Critical 10.0 Cisco Secure Workload Software Security Hardening Release: August 2026 CVE-2026-20231CVE-2026-20315CVE-2026-20317CVE-2026-20318CVE-2026-20319 Critical 10.0 Cisco BroadWorks Out-of-Band Blind XML External Entity Injection Vulnerability CVE-2026-20320 High 7.5 Cisco Unified Intelligence Center SQL Injection Vulnerability CVE-2026-20327 Medium 6.5 Cisco RoomOS Stack Overflow Vulnerability CVE-2026-20302 Medium 6.1 Cisco Industrial Ethernet 1000 Series Switches Stored Cross-Site Scripting

Cisco Security Advisories guidance

Vendor revision: Aug 19, 2026

Cisco has released software updates that address this vulnerability.

CISA KEVNot listedBased on the latest collected catalog

EPSS0.5%Estimated 30-day exploitation probability

Ransomware useNot markedCISA KEV ransomware field

Threat actors0Source-linked actor relationships

Overview

What is CVE-2026-20177?

A vulnerability in the handling of management plane packets by Cisco Industrial Ethernet (IE) 1000 Series Switches could allow an unauthenticated, remote attacker to cause the device manager, SSH, or API to become inaccessible.This vulnerability is due to insufficient protection against management plane flooding attacks.

An attacker could exploit this vulnerability by sending a high rate of ICMP, SSH, or HTTP traffic to an affected device. A successful exploit could allow the attacker to cause the CPU of the device to increase, resulting in a denial of service (DoS) condition on the device manager web GUI, SSH, or API.

Data traffic through the device is not affected.

Source: NVD