CVE-2026-20177 Cisco Industrial Ethernet 1000 Series Switches Denial of Service Vulnerability
Remote unauthenticated attackers can cause a denial of service on management interfaces by flooding the device with high-rate traffic.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-20177?
CVE-2026-20177 is a medium-severity denial of service vulnerability in Cisco Industrial Ethernet Switches, published on 19 Aug 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
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.
Weakness: CWE-770
Which versions are affected by CVE-2026-20177?
How do I fix CVE-2026-20177?
No fix has been published for CVE-2026-20177 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-20177 being exploited?
There is no known exploitation of CVE-2026-20177 in the wild and no public exploit code.
Sources
Also known as GHSA-rvq7-6xgp-76jg.