# CVE-2025-20241

## Summary

- **CVE ID:** CVE-2025-20241
- **Severity:** HIGH
- **CVSS Score:** 7.4 (CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
- **CWE:** CWE-733
- **Published:** Aug 27, 2025
- **Last Modified:** Mar 12, 2026

## Description

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.

## Affected Products

- Cisco — Cisco NX-OS Software (9.2(3))
- Cisco — Cisco NX-OS Software (7.0(3)I5(2))
- Cisco — Cisco NX-OS Software (6.0(2)A8(7a))
- Cisco — Cisco NX-OS Software (7.0(3)I4(5))
- Cisco — Cisco NX-OS Software (7.0(3)I4(6))
- Cisco — Cisco NX-OS Software (7.0(3)I4(3))
- Cisco — Cisco NX-OS Software (9.2(2v))
- Cisco — Cisco NX-OS Software (7.0(3)I4(7))
- Cisco — Cisco NX-OS Software (7.0(3)I4(1))
- Cisco — Cisco NX-OS Software (7.0(3)I4(8))
- Cisco — Cisco NX-OS Software (7.0(3)I4(2))
- Cisco — Cisco NX-OS Software (6.0(2)A8(11))
- Cisco — Cisco NX-OS Software (9.2(1))
- Cisco — Cisco NX-OS Software (9.2(2t))
- Cisco — Cisco NX-OS Software (9.2(3y))
- Cisco — Cisco NX-OS Software (7.0(3)I4(1t))
- Cisco — Cisco NX-OS Software (7.0(3)I7(6z))
- Cisco — Cisco NX-OS Software (9.3(2))
- Cisco — Cisco NX-OS Software (7.0(3)F3(3))
- Cisco — Cisco NX-OS Software (7.0(3)I7(3z))
- Cisco — Cisco NX-OS Software (7.0(3)IM7(2))
- Cisco — Cisco NX-OS Software (6.0(2)A8(11b))
- Cisco — Cisco NX-OS Software (7.0(3)I7(5a))
- Cisco — Cisco NX-OS Software (7.0(3)I6(1))
- Cisco — Cisco NX-OS Software (7.0(3)I5(3b))
- Cisco — Cisco NX-OS Software (9.2(4))
- Cisco — Cisco NX-OS Software (6.0(2)A8(10))
- Cisco — Cisco NX-OS Software (6.0(2)A8(2))
- Cisco — Cisco NX-OS Software (7.0(3)IC4(4))
- Cisco — Cisco NX-OS Software (7.0(3)F3(3c))
- Cisco — Cisco NX-OS Software (7.0(3)F3(1))
- Cisco — Cisco NX-OS Software (7.0(3)F3(5))
- Cisco — Cisco NX-OS Software (7.0(3)I7(2))
- Cisco — Cisco NX-OS Software (7.0(3)I5(3))
- Cisco — Cisco NX-OS Software (7.0(3)I7(3))
- Cisco — Cisco NX-OS Software (6.0(2)A8(6))
- Cisco — Cisco NX-OS Software (7.0(3)I6(2))
- Cisco — Cisco NX-OS Software (6.0(2)A8(5))
- Cisco — Cisco NX-OS Software (9.3(1))
- Cisco — Cisco NX-OS Software (6.0(2)A8(7))
- Cisco — Cisco NX-OS Software (7.0(3)I7(6))
- Cisco — Cisco NX-OS Software (6.0(2)A8(11a))
- Cisco — Cisco NX-OS Software (7.0(3)I4(8z))
- Cisco — Cisco NX-OS Software (7.0(3)I4(9))
- Cisco — Cisco NX-OS Software (7.0(3)I7(4))
- Cisco — Cisco NX-OS Software (7.0(3)I7(7))
- Cisco — Cisco NX-OS Software (6.0(2)A8(9))
- Cisco — Cisco NX-OS Software (6.0(2)A8(1))
- Cisco — Cisco NX-OS Software (6.0(2)A8(10a))
- Cisco — Cisco NX-OS Software (7.0(3)I5(1))
- Cisco — Cisco NX-OS Software (9.3(1z))
- Cisco — Cisco NX-OS Software (9.2(2))
- Cisco — Cisco NX-OS Software (7.0(3)F3(4))
- Cisco — Cisco NX-OS Software (7.0(3)I4(8b))
- Cisco — Cisco NX-OS Software (6.0(2)A8(3))
- Cisco — Cisco NX-OS Software (7.0(3)I4(6t))
- Cisco — Cisco NX-OS Software (7.0(3)I5(3a))
- Cisco — Cisco NX-OS Software (6.0(2)A8(8))
- Cisco — Cisco NX-OS Software (7.0(3)I7(5))
- Cisco — Cisco NX-OS Software (7.0(3)F3(3a))
- Cisco — Cisco NX-OS Software (6.0(2)A8(4))
- Cisco — Cisco NX-OS Software (7.0(3)I4(8a))
- Cisco — Cisco NX-OS Software (7.0(3)F3(2))
- Cisco — Cisco NX-OS Software (7.0(3)I4(4))
- Cisco — Cisco NX-OS Software (7.0(3)I7(1))
- Cisco — Cisco NX-OS Software (7.0(3)IA7(2))
- Cisco — Cisco NX-OS Software (7.0(3)IA7(1))
- Cisco — Cisco NX-OS Software (6.0(2)A8(7b))
- Cisco — Cisco NX-OS Software (6.0(2)A8(4a))
- Cisco — Cisco NX-OS Software (9.3(3))
- Cisco — Cisco NX-OS Software (7.0(3)I7(8))
- Cisco — Cisco NX-OS Software (9.3(4))
- Cisco — Cisco NX-OS Software (9.3(5))
- Cisco — Cisco NX-OS Software (7.0(3)I7(9))
- Cisco — Cisco NX-OS Software (9.3(6))
- Cisco — Cisco NX-OS Software (10.1(2))
- Cisco — Cisco NX-OS Software (10.1(1))
- Cisco — Cisco NX-OS Software (9.3(5w))
- Cisco — Cisco NX-OS Software (9.3(7))
- Cisco — Cisco NX-OS Software (9.3(7k))
- Cisco — Cisco NX-OS Software (7.0(3)I7(9w))
- Cisco — Cisco NX-OS Software (10.2(1))
- Cisco — Cisco NX-OS Software (9.3(7a))
- Cisco — Cisco NX-OS Software (9.3(8))
- Cisco — Cisco NX-OS Software (7.0(3)I7(10))
- Cisco — Cisco NX-OS Software (10.2(1q))
- Cisco — Cisco NX-OS Software (10.2(2))
- Cisco — Cisco NX-OS Software (9.3(9))
- Cisco — Cisco NX-OS Software (10.1(2t))
- Cisco — Cisco NX-OS Software (10.2(3))
- Cisco — Cisco NX-OS Software (10.2(3t))
- Cisco — Cisco NX-OS Software (9.3(10))
- Cisco — Cisco NX-OS Software (10.2(2a))
- Cisco — Cisco NX-OS Software (10.3(1))
- Cisco — Cisco NX-OS Software (10.2(4))
- Cisco — Cisco NX-OS Software (10.3(2))
- Cisco — Cisco NX-OS Software (9.3(11))
- Cisco — Cisco NX-OS Software (10.3(3))
- Cisco — Cisco NX-OS Software (10.2(5))
- Cisco — Cisco NX-OS Software (9.3(12))
- Cisco — Cisco NX-OS Software (10.2(3v))
- Cisco — Cisco NX-OS Software (10.4(1))
- Cisco — Cisco NX-OS Software (10.3(99w))
- Cisco — Cisco NX-OS Software (10.2(6))
- Cisco — Cisco NX-OS Software (10.3(3w))
- Cisco — Cisco NX-OS Software (10.3(99x))
- Cisco — Cisco NX-OS Software (10.3(3o))
- Cisco — Cisco NX-OS Software (10.3(4))
- Cisco — Cisco NX-OS Software (10.3(3p))
- Cisco — Cisco NX-OS Software (10.3(4a))
- Cisco — Cisco NX-OS Software (10.4(2))
- Cisco — Cisco NX-OS Software (10.3(3q))
- Cisco — Cisco NX-OS Software (9.3(13))
- Cisco — Cisco NX-OS Software (10.3(5))
- Cisco — Cisco NX-OS Software (10.2(7))
- Cisco — Cisco NX-OS Software (10.4(3))
- Cisco — Cisco NX-OS Software (10.3(3x))
- Cisco — Cisco NX-OS Software (10.3(4g))
- Cisco — Cisco NX-OS Software (10.5(1))
- Cisco — Cisco NX-OS Software (10.2(8))
- Cisco — Cisco NX-OS Software (10.3(3r))
- Cisco — Cisco NX-OS Software (10.3(6))
- Cisco — Cisco NX-OS Software (9.3(14))
- Cisco — Cisco NX-OS Software (10.4(4))
- Cisco — Cisco NX-OS Software (10.3(4h))
- Cisco — Cisco NX-OS Software (10.5(2))
- Cisco — Cisco NX-OS Software (10.4(4g))

## References

- [CNA](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-n39k-isis-dos-JhJA8Rfx)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.27%
- **EPSS Percentile:** 18.3

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-10._