CVE-2025-20311
HIGH EPSS 8.6%
Published Sep 24, 20259mo ago · Modified Jun 17, 20261w ago
7.4 CVSS 3.1
Published Sep 24, 2025 9mo ago
Last Modified Jun 17, 2026 1w ago
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.
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H Attack Vector Adjacent
Attack Complexity Low
Privileges Required None
User Interaction None
Scope Changed
Confidentiality None
Integrity None
Availability High
Threat Intelligence
EPSS Exploit Probability
8.6% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available
Weaknesses 1
CWE-19
References 1
- sec.cloudapps.cisco.com https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-cat9k-PtmD7bgy
Remediation
No remediation data recorded yet
Check vendor advisories and the NVD entry for patch availability.