CVE-2025-20160: High severity Cisco IOS Software vulnerability
Published Sep 24, 2025
·Updated
A vulnerability in the implementation of the TACACS+ protocol in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to view sensitive data or bypass authentication. This vulnerability exists because the system does not properly check whether the required TACACS+ shared secret is configured. A machine-in-the-middle attacker could exploit this vulnerability by intercepting and reading unencrypted TACACS+ messages or impersonating the TACACS+ server and falsely accepting arbitrary authentication requests. A successful exploit could allow the attacker to view sensitive information in a TACACS+ message or bypass authentication and gain access to the affected device.
Affected Software
361 affected components
Cisco IOS Software
Cisco IOS XE Software
Cisco IOS=15.2\(4\)e6
Cisco IOS=15.2\(4\)e7
Cisco IOS=15.2\(4\)e8
Cisco IOS=15.2\(4\)e9
Cisco IOS=15.2\(4\)e10
Cisco IOS=15.2\(4\)e10a
Cisco IOS=15.2\(4\)e10d
Cisco IOS=15.2\(6\)e1
Cisco IOS=15.2\(6\)e2
Cisco IOS=15.2\(6\)e2a
Cisco IOS=15.2\(6\)e2b
Cisco IOS=15.2\(6\)e3
Cisco IOS=15.2\(6\)eb
Cisco IOS=15.2\(7\)e
Cisco IOS=15.2\(7\)e0a
Cisco IOS=15.2\(7\)e0b
Cisco IOS=15.2\(7\)e0s
Cisco IOS=15.2\(7\)e1
Cisco IOS=15.2\(7\)e1a
Cisco IOS=15.2\(7\)e2
Cisco IOS=15.2\(7\)e2a
Cisco IOS=15.2\(7\)e3
Cisco IOS=15.2\(7\)e3k
Cisco IOS=15.2\(7\)e4
Cisco IOS=15.2\(7\)e5
Cisco IOS=15.2\(7\)e6
Cisco IOS=15.2\(7\)e7
Cisco IOS=15.2\(7\)e8
Cisco IOS=15.2\(7\)e9
Cisco IOS=15.2\(7\)e10
Cisco IOS=15.2\(7\)e11
Cisco IOS=15.2\(7\)e12
Cisco IOS=15.2\(7a\)e0b
Cisco IOS=15.2\(7b\)e0b
Cisco IOS=15.2\(8\)e
Cisco IOS=15.2\(8\)e1
Cisco IOS=15.2\(8\)e2
Cisco IOS=15.2\(8\)e3
Cisco IOS=15.2\(8\)e4
Cisco IOS=15.2\(8\)e5
Cisco IOS=15.2\(8\)e6
Cisco IOS=15.2\(8\)e7
Cisco IOS=15.5\(1\)sy2
Cisco IOS=15.5\(1\)sy3
Cisco IOS=15.5\(1\)sy4
Cisco IOS=15.5\(1\)sy5
Cisco IOS=15.5\(1\)sy6
Cisco IOS=15.5\(1\)sy7
Cisco IOS=15.5\(1\)sy8
Cisco IOS=15.5\(1\)sy9
Cisco IOS=15.5\(1\)sy10
Cisco IOS=15.5\(1\)sy11
Cisco IOS=15.5\(1\)sy12
Cisco IOS=15.5\(1\)sy13
Cisco IOS=15.5\(1\)sy14
Cisco IOS=15.5\(1\)sy15
Cisco IOS=15.5\(3\)m7
Cisco IOS=15.5\(3\)m8
Cisco IOS=15.5\(3\)m9
Cisco IOS=15.5\(3\)m10
Cisco IOS=15.5\(3\)s8
Cisco IOS=15.5\(3\)s9
Cisco IOS=15.5\(3\)s9a
Cisco IOS=15.5\(3\)s10
Cisco IOS=15.6\(2\)sp5
Cisco IOS=15.6\(2\)sp6
Cisco IOS=15.6\(2\)sp7
Cisco IOS=15.6\(2\)sp8
Cisco IOS=15.6\(2\)sp9
Cisco IOS=15.6\(3\)m4
Cisco IOS=15.6\(3\)m5
Cisco IOS=15.6\(3\)m6
Cisco IOS=15.6\(3\)m6a
Cisco IOS=15.6\(3\)m6b
Cisco IOS=15.6\(3\)m7
Cisco IOS=15.6\(3\)m8
Cisco IOS=15.6\(3\)m9
Cisco IOS=15.7\(3\)m2
Cisco IOS=15.7\(3\)m3
Cisco IOS=15.7\(3\)m4
Cisco IOS=15.7\(3\)m4a
Cisco IOS=15.7\(3\)m4b
Cisco IOS=15.7\(3\)m5
Cisco IOS=15.7\(3\)m6
Cisco IOS=15.7\(3\)m7
Cisco IOS=15.7\(3\)m8
Cisco IOS=15.7\(3\)m9
Cisco IOS=15.8\(3\)m
Cisco IOS=15.8\(3\)m0a
Cisco IOS=15.8\(3\)m0b
Cisco IOS=15.8\(3\)m1
Cisco IOS=15.8\(3\)m1a
Cisco IOS=15.8\(3\)m2
Cisco IOS=15.8\(3\)m2a
Cisco IOS=15.8\(3\)m3
Cisco IOS=15.8\(3\)m3a
Cisco IOS=15.8\(3\)m3b
Cisco IOS=15.8\(3\)m4
Cisco IOS=15.8\(3\)m5
Cisco IOS=15.8\(3\)m6
Cisco IOS=15.8\(3\)m7
Cisco IOS=15.8\(3\)m8
Cisco IOS=15.8\(3\)m9
Cisco IOS=15.9\(3\)m
Cisco IOS=15.9\(3\)m0a
Cisco IOS=15.9\(3\)m1
Cisco IOS=15.9\(3\)m2
Cisco IOS=15.9\(3\)m2a
Cisco IOS=15.9\(3\)m3
Cisco IOS=15.9\(3\)m3a
Cisco IOS=15.9\(3\)m3b
Cisco IOS=15.9\(3\)m4
Cisco IOS=15.9\(3\)m4a
Cisco IOS=15.9\(3\)m5
Cisco IOS=15.9\(3\)m6
Cisco IOS=15.9\(3\)m6a
Cisco IOS=15.9\(3\)m6b
Cisco IOS=15.9\(3\)m7
Cisco IOS=15.9\(3\)m7a
Cisco IOS=15.9\(3\)m8
Cisco IOS=15.9\(3\)m8b
Cisco IOS=15.9\(3\)m9
Cisco IOS=15.9\(3\)m10
Cisco IOS=15.9\(3\)m11
Cisco IOS XE=3.8.6e
Cisco IOS XE=3.8.7e
Cisco IOS XE=3.8.8e
Cisco IOS XE=3.8.9e
Cisco IOS XE=3.8.10e
Cisco IOS XE=3.10.1e
Cisco IOS XE=3.10.2e
Cisco IOS XE=3.10.3e
Cisco IOS XE=3.11.0e
Cisco IOS XE=3.11.1ae
Cisco IOS XE=3.11.1e
Cisco IOS XE=3.11.2e
Cisco IOS XE=3.11.3ae
Cisco IOS XE=3.11.3e
Cisco IOS XE=3.11.4e
Cisco IOS XE=3.11.5e
Cisco IOS XE=3.11.6e
Cisco IOS XE=3.11.7e
Cisco IOS XE=3.11.8e
Cisco IOS XE=3.11.9e
Cisco IOS XE=3.11.10e
Cisco IOS XE=3.11.11e
Cisco IOS XE=3.11.12e
Cisco IOS XE=3.16.8s
Cisco IOS XE=3.16.9s
Cisco IOS XE=3.16.10s
Cisco IOS XE=3.18.5sp
Cisco IOS XE=3.18.6sp
Cisco IOS XE=3.18.7sp
Cisco IOS XE=3.18.8asp
Cisco IOS XE=3.18.9sp
Cisco IOS XE=16.6.5
Cisco IOS XE=16.6.5a
Cisco IOS XE=16.6.6
Cisco IOS XE=16.6.7
Cisco IOS XE=16.6.8
Cisco IOS XE=16.6.9
Cisco IOS XE=16.6.10
Cisco IOS XE=16.8.1
Cisco IOS XE=16.8.1a
Cisco IOS XE=16.8.1b
Cisco IOS XE=16.8.1c
Cisco IOS XE=16.8.1d
Cisco IOS XE=16.8.1e
Cisco IOS XE=16.8.1s
Cisco IOS XE=16.8.2
Cisco IOS XE=16.8.3
Cisco IOS XE=16.9.1
Cisco IOS XE=16.9.1a
Cisco IOS XE=16.9.1b
Cisco IOS XE=16.9.1s
Cisco IOS XE=16.9.2
Cisco IOS XE=16.9.3
Cisco IOS XE=16.9.3a
Cisco IOS XE=16.9.4
Cisco IOS XE=16.9.5
Cisco IOS XE=16.9.5f
Cisco IOS XE=16.9.6
Cisco IOS XE=16.9.7
Cisco IOS XE=16.9.8
Cisco IOS XE=16.10.1
Cisco IOS XE=16.10.1a
Cisco IOS XE=16.10.1b
Cisco IOS XE=16.10.1c
Cisco IOS XE=16.10.1d
Cisco IOS XE=16.10.1e
Cisco IOS XE=16.10.1f
Cisco IOS XE=16.10.1g
Cisco IOS XE=16.10.1s
Cisco IOS XE=16.10.2
Cisco IOS XE=16.10.3
Cisco IOS XE=16.11.1
Cisco IOS XE=16.11.1a
Cisco IOS XE=16.11.1b
Cisco IOS XE=16.11.1s
Cisco IOS XE=16.11.2
Cisco IOS XE=16.12.1
Cisco IOS XE=16.12.1a
Cisco IOS XE=16.12.1c
Cisco IOS XE=16.12.1s
Cisco IOS XE=16.12.1t
Cisco IOS XE=16.12.1w
Cisco IOS XE=16.12.1x
Cisco IOS XE=16.12.1y
Cisco IOS XE=16.12.1z1
Cisco IOS XE=16.12.1z2
Cisco IOS XE=16.12.2
Cisco IOS XE=16.12.2a
Cisco IOS XE=16.12.2s
Cisco IOS XE=16.12.3
Cisco IOS XE=16.12.3a
Cisco IOS XE=16.12.3s
Cisco IOS XE=16.12.4
Cisco IOS XE=16.12.4a
Cisco IOS XE=16.12.5
Cisco IOS XE=16.12.5a
Cisco IOS XE=16.12.5b
Cisco IOS XE=16.12.6
Cisco IOS XE=16.12.6a
Cisco IOS XE=16.12.7
Cisco IOS XE=16.12.8
Cisco IOS XE=16.12.9
Cisco IOS XE=16.12.10
Cisco IOS XE=16.12.10a
Cisco IOS XE=16.12.11
Cisco IOS XE=16.12.12
Cisco IOS XE=16.12.13
Cisco IOS XE=17.1.1
Cisco IOS XE=17.1.1a
Cisco IOS XE=17.1.1s
Cisco IOS XE=17.1.1t
Cisco IOS XE=17.1.3
Cisco IOS XE=17.2.1
Cisco IOS XE=17.2.1a
Cisco IOS XE=17.2.1r
Cisco IOS XE=17.2.1v
Cisco IOS XE=17.2.2
Cisco IOS XE=17.2.3
Cisco IOS XE=17.3.1
Cisco IOS XE=17.3.1a
Cisco IOS XE=17.3.1w
Cisco IOS XE=17.3.1x
Cisco IOS XE=17.3.1z
Cisco IOS XE=17.3.2
Cisco IOS XE=17.3.2a
Cisco IOS XE=17.3.3
Cisco IOS XE=17.3.4
Cisco IOS XE=17.3.4a
Cisco IOS XE=17.3.4b
Cisco IOS XE=17.3.4c
Cisco IOS XE=17.3.5
Cisco IOS XE=17.3.5a
Cisco IOS XE=17.3.5b
Cisco IOS XE=17.3.6
Cisco IOS XE=17.3.7
Cisco IOS XE=17.3.8
Cisco IOS XE=17.3.8a
Cisco IOS XE=17.4.1
Cisco IOS XE=17.4.1a
Cisco IOS XE=17.4.1b
Cisco IOS XE=17.4.2
Cisco IOS XE=17.4.2a
Cisco IOS XE=17.5.1
Cisco IOS XE=17.5.1a
Cisco IOS XE=17.6.1
Cisco IOS XE=17.6.1a
Cisco IOS XE=17.6.1w
Cisco IOS XE=17.6.1x
Cisco IOS XE=17.6.1y
Cisco IOS XE=17.6.1z
Cisco IOS XE=17.6.1z1
Cisco IOS XE=17.6.2
Cisco IOS XE=17.6.3
Cisco IOS XE=17.6.3a
Cisco IOS XE=17.6.4
Cisco IOS XE=17.6.5
Cisco IOS XE=17.6.5a
Cisco IOS XE=17.6.6
Cisco IOS XE=17.6.6a
Cisco IOS XE=17.6.7
Cisco IOS XE=17.6.8
Cisco IOS XE=17.6.8a
Cisco IOS XE=17.7.1
Cisco IOS XE=17.7.1a
Cisco IOS XE=17.7.1b
Cisco IOS XE=17.7.2
Cisco IOS XE=17.8.1
Cisco IOS XE=17.8.1a
Cisco IOS XE=17.9.1
Cisco IOS XE=17.9.1a
Cisco IOS XE=17.9.1w
Cisco IOS XE=17.9.1x
Cisco IOS XE=17.9.1x1
Cisco IOS XE=17.9.1y
Cisco IOS XE=17.9.1y1
Cisco IOS XE=17.9.2
Cisco IOS XE=17.9.2a
Cisco IOS XE=17.9.3
Cisco IOS XE=17.9.3a
Cisco IOS XE=17.9.4
Cisco IOS XE=17.9.4a
Cisco IOS XE=17.9.5
Cisco IOS XE=17.9.5a
Cisco IOS XE=17.9.5b
Cisco IOS XE=17.9.5e
Cisco IOS XE=17.9.5f
Cisco IOS XE=17.9.6
Cisco IOS XE=17.9.6a
Cisco IOS XE=17.9.7
Cisco IOS XE=17.9.7a
Cisco IOS XE=17.9.7b
Cisco IOS XE=17.10.1
Cisco IOS XE=17.10.1a
Cisco IOS XE=17.10.1b
Cisco IOS XE=17.11.1
Cisco IOS XE=17.11.1a
Cisco IOS XE=17.11.99sw
Cisco IOS XE=17.12.1
Cisco IOS XE=17.12.1a
Cisco IOS XE=17.12.1w
Cisco IOS XE=17.12.1x
Cisco IOS XE=17.12.1y
Cisco IOS XE=17.12.1z
Cisco IOS XE=17.12.1z1
Cisco IOS XE=17.12.1z2
Cisco IOS XE=17.12.1z3
Cisco IOS XE=17.12.1z4
Cisco IOS XE=17.12.2
Cisco IOS XE=17.12.2a
Cisco IOS XE=17.12.3
Cisco IOS XE=17.12.3a
Cisco IOS XE=17.12.4
Cisco IOS XE=17.12.4a
Cisco IOS XE=17.12.4b
Cisco IOS XE=17.12.5
Cisco IOS XE=17.12.5a
Cisco IOS XE=17.12.5b
Cisco IOS XE=17.12.5c
Cisco IOS XE=17.13.1
Cisco IOS XE=17.13.1a
Cisco IOS XE=17.14.1
Cisco IOS XE=17.14.1a
Cisco IOS XE=17.15.1
Cisco IOS XE=17.15.1a
Cisco IOS XE=17.15.1b
Cisco IOS XE=17.15.1w
Cisco IOS XE=17.15.1x
Cisco IOS XE=17.15.1y
Cisco IOS XE=17.15.2
Cisco IOS XE=17.15.2a
Cisco IOS XE=17.15.2b
Cisco IOS XE=17.15.2c
Cisco IOS XE=17.15.3
Cisco IOS XE=17.15.3a
Cisco IOS XE=17.15.3b
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Configuration
Configure and verify the TACACS+ shared secret on the device so the system properly checks it and does not falsely accept arbitrary authentication requests or bypass authentication.
Cisco IOS Software / Cisco IOS XE Software (TACACS+ implementation) TACACS+ shared secret configured = Ensure the required TACACS+ shared secret is correctly configured - Compensating control
Mitigate the risk of unencrypted interception by ensuring TACACS+ traffic is protected (e.g., via a trusted network path/VPN) so a man-in-the-middle cannot intercept and read TACACS+ messages.
Event History
Sep 24, 2025
CVE Published
via MITRE·05:10 PM
Data Sourced
via MITRE·05:10 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·06:15 PM
DescriptionSeverityWeaknessAffected Software
Frequently Asked Questions
1
What is the severity of CVE-2025-20160?
CVE-2025-20160 has a critical severity rating due to its potential to allow remote attackers to bypass authentication.
2
How do I fix CVE-2025-20160?
To fix CVE-2025-20160, update your Cisco IOS or IOS XE software to the latest fixed version provided by Cisco.
3
Who is affected by CVE-2025-20160?
Organizations using Cisco IOS Software and Cisco IOS XE Software are affected by CVE-2025-20160.
4
What type of attack is possible with CVE-2025-20160?
CVE-2025-20160 allows an unauthenticated remote attacker to view sensitive data or bypass authentication.
5
When was CVE-2025-20160 disclosed?
CVE-2025-20160 was disclosed on the date it was identified in early 2025.