CVE-2025-20140 Denial of service in Cisco IOS XE Software

High 7.4 Published 7 May 2025 Updated 7 May 2025

An unauthenticated adjacent attacker can cause a denial of service on Cisco IOS XE Wireless LAN Controllers by exhausting memory via IPv6 requests.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Local or same network only
Victim action needed: Not needed
Fix: None listed

What is CVE-2025-20140?

CVE-2025-20140 is a high-severity denial of service vulnerability in Cisco Ios Xe, published on 7 May 2025. It can only be exploited from the same machine or local network, with no action from the victim.

Official description

A vulnerability in the Wireless Network Control daemon (wncd) of Cisco IOS XE Software for Wireless LAN Controllers (WLCs) could allow an unauthenticated, adjacent wireless attacker to cause a denial of service (DoS) condition. This vulnerability is due to improper memory management. An attacker could exploit this vulnerability by sending a series of IPv6 network requests from an associated wireless IPv6 client to an affected device. To associate a client to a device, an attacker may first need to authenticate to the network, or associate freely in the case of a configured open network. A successful exploit could allow the attacker to cause the wncd process to consume available memory and eventually cause the device to stop responding, resulting in a DoS condition.

Weakness: CWE-789

Which versions are affected by CVE-2025-20140?

It affects 1 product.

Products include Cisco Ios Xe.

How do I fix CVE-2025-20140?

No fix has been published for CVE-2025-20140 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-2025-20140 being exploited?

There is no known exploitation of CVE-2025-20140 in the wild and no public exploit code.

All Cisco Ios Xe vulnerabilities

Sources

Also known as GHSA-pxp6-97q7-w6wm.