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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.

PUBLISHED Reserved 2024-10-10 | Published 2025-09-24 | Updated 2025-09-24 | Assigner cisco




HIGH: 7.4CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Problem types

Data Handling

Product status

16.6.1
affected

16.6.2
affected

16.6.3
affected

16.6.4
affected

16.6.5
affected

16.6.4a
affected

16.6.6
affected

16.6.7
affected

16.6.8
affected

16.6.9
affected

16.6.10
affected

16.7.1
affected

16.8.1
affected

16.8.1a
affected

16.8.1s
affected

16.9.1
affected

16.9.2
affected

16.9.1s
affected

16.9.3
affected

16.9.4
affected

16.9.5
affected

16.9.6
affected

16.9.7
affected

16.9.8
affected

16.10.1
affected

16.10.1s
affected

16.10.1e
affected

16.11.1
affected

16.11.1b
affected

16.11.1s
affected

16.12.1
affected

16.12.1s
affected

16.12.1c
affected

16.12.2
affected

16.12.3
affected

16.12.8
affected

16.12.2s
affected

16.12.4
affected

16.12.3s
affected

16.12.3a
affected

16.12.4a
affected

16.12.5
affected

16.12.6
affected

16.12.5b
affected

16.12.6a
affected

16.12.7
affected

16.12.14
affected

17.1.1
affected

17.1.1s
affected

17.1.1t
affected

17.1.3
affected

17.2.1
affected

17.2.1a
affected

17.3.1
affected

17.3.2
affected

17.3.3
affected

17.3.2a
affected

17.3.4
affected

17.3.5
affected

17.3.6
affected

17.3.4b
affected

17.3.7
affected

17.3.8
affected

17.3.8a
affected

17.4.1
affected

17.5.1
affected

17.6.1
affected

17.6.2
affected

17.6.3
affected

17.6.1y
affected

17.6.4
affected

17.6.5
affected

17.6.6
affected

17.6.6a
affected

17.6.5a
affected

17.6.7
affected

17.6.8
affected

17.7.1
affected

17.10.1
affected

17.10.1b
affected

17.8.1
affected

17.9.1
affected

17.9.2
affected

17.9.3
affected

17.9.4
affected

17.9.5
affected

17.9.4a
affected

17.9.6
affected

17.9.6a
affected

17.11.1
affected

17.12.1
affected

17.12.2
affected

17.12.3
affected

17.12.4
affected

17.12.1z3
affected

17.13.1
affected

17.14.1
affected

17.11.99SW
affected

17.15.1
affected

17.15.2
affected

17.15.2a
affected

17.15.2b
affected

17.16.1
affected

References

sec.cloudapps.cisco.com/...yAdvisory/cisco-sa-cat9k-PtmD7bgy (cisco-sa-cat9k-PtmD7bgy)

cve.org (CVE-2025-20311)

nvd.nist.gov (CVE-2025-20311)

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