A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic. This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition.

Metrics

No CVSS v4.0

Attack Vector Adjacent Network

Attack Complexity Low

Privileges Required None

Scope Changed

Confidentiality Impact None

Integrity Impact None

Availability Impact High

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

Exploitation none

Automatable no

Technical Impact partial

Affected Vendors & Products

Vendors Products
Cisco
  • Ios Xe Software

No data.

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References
Link Providers
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-PtmD7bgy cve-icon cve-icon
History

Thu, 25 Sep 2025 08:30:00 +0000

Type Values Removed Values Added
First Time appeared Cisco
Cisco ios Xe Software
Vendors & Products Cisco
Cisco ios Xe Software

Wed, 24 Sep 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Wed, 24 Sep 2025 17:30:00 +0000

Type Values Removed Values Added
Description A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic. This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition.
Weaknesses CWE-19
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H'}
cve-icon MITRE

Status: PUBLISHED

Assigner: cisco

Published: 2025-09-24T17:12:06.928Z

Updated: 2025-09-30T14:28:26.310Z

Reserved: 2024-10-10T19:15:13.253Z

Link: CVE-2025-20311

cve-icon Vulnrichment

Updated: 2025-09-24T18:07:35.601Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-09-24T18:15:34.757

Modified: 2025-09-26T14:32:53.583

Link: CVE-2025-20311

cve-icon Redhat

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