PT-2025-34887 · Cisco · Cisco Nexus 3000 Series Switches+2

Published

2025-08-27

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Updated

2025-09-22

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CVE-2025-20241

CVSS v3.1

7.4

High

VectorAV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
Name of the Vulnerable Software and Affected Versions Cisco NX-OS Software for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches
Description A vulnerability exists in the Intermediate System-to-Intermediate System (IS-IS) feature. An unauthenticated, adjacent attacker could exploit this issue by sending a crafted IS-IS packet, causing the IS-IS process to unexpectedly restart and potentially leading to a denial of service (DoS) condition and device reload. The vulnerability is due to insufficient input validation when parsing an incoming IS-IS packet. The IS-IS protocol is a routing protocol, and an attacker must be Layer 2-adjacent to the affected device to exploit this vulnerability.
Recommendations At the moment, there is no information about a newer version that contains a fix for this vulnerability.

DoS

Weakness Enumeration

CWE-733

Related Identifiers

BDU:2025-10439
CVE-2025-20241

Affected Products

Cisco Nx-Os
Cisco Nexus 3000 Series Switches
Cisco Nexus 9000 Series Switches