CVE-2025-20316: cisco cisco ios xe software Improper Access Control

Vulnerability summary

CVE-2025-20316 is a medium (CVSS 5.3) Improper Access Control vulnerability in cisco cisco ios xe software. EPSS estimates a 0.34% chance of exploitation in the next 30 days, higher than 25.7% of scored vulnerabilities.

Timeline

1. 24-09-2025
   PublishedVulnerability first disclosed.
2. 24-09-2025
   Last modifiedVulnerability information updated.

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.

• CWE-284Improper Access ControlThe product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.