CVE-2025-20241
A vulnerability in the Intermediate System-to-Intermediate System (IS-IS) feature of Cisco NX-OS Software for Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an unauthenticated, adjacent attacker to cause the IS-IS process to unexpectedly restart, which could cause an affected device to reload. This vulnerability is due to insufficient input validation when parsing an ingress IS-IS packet. An attacker could exploit this vulnerability by sending a crafted IS-IS packet to an affected device. A successful exploit could allow the attacker to cause the unexpected restart of the IS-IS process, which could cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The IS-IS protocol is a routing protocol. To exploit this vulnerability, an attacker must be Layer 2-adjacent to the affected device.
Scoring
- Severity
- HIGH
- CVSS base score
- 7.4
- CVSS vector
- CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- EPSS probability
- 0.27%
- CWE
- CWE-733
- Published
- 2025-08-27
- Last modified
- 2026-03-12
Affected products
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
- Cisco Cisco NX-OS Software
Weakness type
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