CVE-2025-20316

Medium

Description

A vulnerability in the access control list (ACL) programming of Cisco IOS XE Software for Cisco Catalyst 9500X and 9600X Series Switches could allow an unauthenticated, remote attacker to bypass a configured ACL on an affected device. This vulnerability is due to the flooding of traffic from an unlearned MAC address on a switch virtual interface (SVI) that has an egress ACL applied. An attacker could exploit this vulnerability by causing the VLAN to flush its MAC address table. This condition can also occur if the MAC address table is full. A successful exploit could allow the attacker to bypass an egress ACL on an affected device.

SeverityMedium
CVSS5.3
Exploit probability—
ProductCisco IOS XE Software
PublishedSep 24, 2025
First seenSep 24, 2025

How to fix

Sources list no fixed version or patch link for this vulnerability.

Affected products

ProductAffected versionsFixed in
Cisco Cisco IOS XE Software17.7.1, 17.10.1, 17.10.1b, 17.8.1, 17.9.1, 17.9.2, 17.9.3, 17.9.4, 17.9.5, 17.9.4a, 17.9.6, 17.9.6a, 17.9.7, 17.11.1, 17.12.1, 17.12.2, 17.12.3, 17.12.4, 17.12.5, 17.13.1, 17.14.1, 17.15.1, 17.15.2, 17.15.3, 17.15.2b, 17.16.1, 17.17.1—

Check your version

Choose the product and enter the version you run to see whether it falls in the affected range.

In the Intelligence 360 plan

Attack Surface Management

See the assets tied to your domains, the technologies they run and known vulnerabilities in one list.