CVE-2025-20316
Cisco Catalyst 9500X and 9600X Series Switches ACL Egress Bypass Vulnerability
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.
INFO
Published Date :
Sept. 24, 2025, 6:15 p.m.
Last Modified :
Sept. 24, 2025, 6:15 p.m.
Remotely Exploit :
Yes !
Source :
[email protected]
Affected Products
The following products are affected by CVE-2025-20316
vulnerability.
Even if cvefeed.io is aware of the exact versions of the
products
that
are
affected, the information is not represented in the table below.
No affected product recoded yet
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Apply software updates provided by Cisco.
- Restrict traffic from unlearned MAC addresses.
- Monitor MAC address table for unusual activity.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2025-20316.
| URL | Resource |
|---|---|
| https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-acl-L4K7VXgD |
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2025-20316 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2025-20316
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2025-20316 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2025-20316 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
New CVE Received by [email protected]
Sep. 24, 2025
Action Type Old Value New Value Added 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. Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N Added CWE CWE-284 Added Reference https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-acl-L4K7VXgD