PT-2025-39303 · Cisco · Cisco Catalyst 9500X Series Switches+2

Published 2025-09-24 · Updated 2025-09-25 · CVE-2025-20316

Positive Technologies (AI Summary)

CVSS v3.1

5.3

Medium

Base vector

AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N

Name of the Vulnerable Software and Affected Versions Cisco IOS XE Software for Cisco Catalyst 9500X and 9600X Series Switches (affected versions not specified)

Description A flaw exists in the access control list (ACL) programming that could allow a remote attacker to bypass a configured ACL on an affected device. This is due to the flooding of traffic from an unlearned MAC address on a switch virtual interface (SVI) with an egress ACL applied. An attacker can exploit this by causing the VLAN to flush its MAC address table, or if the MAC address table is full. A successful exploit could allow an attacker to bypass an egress ACL.

Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Improper Access Control

Weakness Enumeration

CWE-284

Related Identifiers

BDU:2025-11734

CVE-2025-20316

Affected Products

Cisco Catalyst 9500X Series Switches

Cisco Catalyst 9600X Series Switches

Cisco Ios Xe

References · 7

• https://bdu.fstec.ru/vul/2025-11734 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2025-20316 · Security Note
• https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-acl-L4K7VXgD · Vendor Advisory
• https://t.me/CVEtracker/33265 · Telegram Post
• https://twitter.com/0dayPublishing/status/1970903570867278100 · Twitter Post
• https://twitter.com/CVEnew/status/1970906975916486842 · Twitter Post
• https://twitter.com/leftSECURE/status/1971300024782111038 · Twitter Post