# CVE-2025-20191

## Summary

- **CVE ID:** CVE-2025-20191
- **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-805
- **Published:** May 7, 2025
- **Last Modified:** Mar 12, 2026

## Description

A vulnerability in the Switch Integrated Security Features (SISF) of Cisco IOS Software, Cisco IOS XE Software, Cisco NX-OS Software, and Cisco Wireless LAN Controller (WLC) AireOS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device.

This vulnerability is due to the incorrect handling of DHCPv6 packets. An attacker could exploit this vulnerability by sending a crafted DHCPv6 packet to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

## Affected Products

- Cisco — Cisco NX-OS Software (8.2(5))
- Cisco — Cisco NX-OS Software (7.3(5)D1(1))
- Cisco — Cisco NX-OS Software (8.4(2))
- Cisco — Cisco NX-OS Software (8.4(3))
- Cisco — Cisco NX-OS Software (9.2(3))
- Cisco — Cisco NX-OS Software (9.2(2v))
- Cisco — Cisco NX-OS Software (7.3(4)D1(1))
- Cisco — Cisco NX-OS Software (8.2(1))
- 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)I7(6z))
- Cisco — Cisco NX-OS Software (9.3(2))
- 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 (7.0(3)I7(5a))
- Cisco — Cisco NX-OS Software (8.1(1))
- Cisco — Cisco NX-OS Software (8.2(2))
- Cisco — Cisco NX-OS Software (8.3(2))
- Cisco — Cisco NX-OS Software (7.3(2)D1(3a))
- Cisco — Cisco NX-OS Software (9.2(4))
- Cisco — Cisco NX-OS Software (8.1(2))
- Cisco — Cisco NX-OS Software (7.3(3)D1(1))
- Cisco — Cisco NX-OS Software (8.2(3))
- Cisco — Cisco NX-OS Software (7.0(3)I7(2))
- Cisco — Cisco NX-OS Software (7.0(3)I7(3))
- Cisco — Cisco NX-OS Software (8.4(1))
- Cisco — Cisco NX-OS Software (7.3(0)DX(1))
- Cisco — Cisco NX-OS Software (7.3(2)D1(1))
- Cisco — Cisco NX-OS Software (9.3(1))
- Cisco — Cisco NX-OS Software (7.0(3)I7(6))
- Cisco — Cisco NX-OS Software (7.3(2)D1(2))
- Cisco — Cisco NX-OS Software (8.2(4))
- 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 (9.3(1z))
- Cisco — Cisco NX-OS Software (9.2(2))
- Cisco — Cisco NX-OS Software (8.1(2a))
- Cisco — Cisco NX-OS Software (7.3(2)D1(3))
- Cisco — Cisco NX-OS Software (7.0(3)I7(5))
- 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 (8.3(1))
- Cisco — Cisco NX-OS Software (7.3(1)D1(1))
- Cisco — Cisco NX-OS Software (7.3(0)D1(1))
- Cisco — Cisco NX-OS Software (9.3(3))
- Cisco — Cisco NX-OS Software (7.3(2)D1(1d))
- Cisco — Cisco NX-OS Software (7.0(3)I7(8))
- Cisco — Cisco NX-OS Software (9.3(4))
- Cisco — Cisco NX-OS Software (7.3(6)D1(1))
- Cisco — Cisco NX-OS Software (8.2(6))
- 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 (8.4(4))
- Cisco — Cisco NX-OS Software (7.3(7)D1(1))
- Cisco — Cisco NX-OS Software (9.3(5w))
- Cisco — Cisco NX-OS Software (8.2(7))
- 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 (7.3(8)D1(1))
- Cisco — Cisco NX-OS Software (9.3(7a))
- Cisco — Cisco NX-OS Software (8.2(7a))
- Cisco — Cisco NX-OS Software (9.3(8))
- Cisco — Cisco NX-OS Software (8.4(4a))
- Cisco — Cisco NX-OS Software (8.4(5))
- Cisco — Cisco NX-OS Software (7.0(3)I7(10))
- Cisco — Cisco NX-OS Software (8.2(8))
- 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 (7.3(9)D1(1))
- Cisco — Cisco NX-OS Software (10.2(3))
- Cisco — Cisco NX-OS Software (8.4(6))
- 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 (8.2(9))
- Cisco — Cisco NX-OS Software (10.3(1))
- Cisco — Cisco NX-OS Software (10.2(4))
- Cisco — Cisco NX-OS Software (8.4(7))
- Cisco — Cisco NX-OS Software (10.3(2))
- Cisco — Cisco NX-OS Software (8.4(6a))
- 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 (8.2(10))
- 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 (8.4(8))
- 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 (8.4(9))
- 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 (8.2(11))
- 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 (10.2(8))
- Cisco — Cisco NX-OS Software (10.3(3r))
- Cisco — Cisco NX-OS Software (9.3(14))
- Cisco — Cisco NX-OS Software (10.3(4h))
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.112.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.8.120.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.143.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.111.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.164.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.109.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.132.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.105.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.170.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.160.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.8.100.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.9.111.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.7.102.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.102.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.133.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.131.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.100.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.131.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.122.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.101.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.112.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.120.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.141.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.141.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.121.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.151.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.130.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.102.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.161.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.151.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.100.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.135.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.135.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.140.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.7.106.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.9.100.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.8.111.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.110.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.110.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.130.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.141.105)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.121.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.8.125.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.150.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.111.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.105.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.108.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.108.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.2.166.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.103.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.3.140.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.6.101.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.4.100.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.160.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.161.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.8.130.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.120.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.121.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.113.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.122.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.130.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.141.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.142.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.171.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.150.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.151.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.162.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.171.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.180.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.181.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.182.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.170.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.183.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.7)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.105)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.106)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.185.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.107)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.11)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.108)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.190.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.10.195.0)
- Cisco — Cisco Wireless LAN Controller (WLC) (8.5.182.12)

## References

- [CNA](https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sisf-dos-ZGwt4DdY)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.24%
- **EPSS Percentile:** 14.5

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