What’s Vulnerable › Products

Cisco IOS vulnerabilities

622 known vulnerabilities, 39 confirmed exploited in the wild (CISA KEV), 22 published in the last 12 months.

Check whether your Cisco IOS version is affected

Exploited Cisco IOS vulnerabilities

• CVE-2008-4128 — Cisco IOS Cross-Site Request Forgery Vulnerability
• CVE-2025-20352 — Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability
• CVE-2023-20109 — Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability
• CVE-2016-6415 — Cisco IOS, IOS XR, and IOS XE IKEv1 Information Disclosure Vulnerability
• CVE-2004-1464 — Cisco IOS Denial-of-Service Vulnerability
• CVE-2017-6742 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability
• CVE-2017-3881 — Cisco IOS and IOS XE Remote Code Execution Vulnerability
• CVE-2018-0180 — Cisco IOS Software Denial-of-Service Vulnerability
• CVE-2018-0179 — Cisco IOS Software Denial-of-Service Vulnerability
• CVE-2018-0175 — Cisco IOS, XR, and XE Software Buffer Overflow Vulnerability
• CVE-2018-0174 — Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability
• CVE-2018-0173 — Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
• CVE-2018-0172 — Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
• CVE-2018-0167 — Cisco IOS, XR, and XE Software Buffer Overflow Vulnerability
• CVE-2018-0161 — Cisco IOS Software Resource Management Errors Vulnerability
• CVE-2018-0159 — Cisco IOS and XE Software Internet Key Exchange Version 1 Denial-of-Service Vulnerability
• CVE-2018-0158 — Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability
• CVE-2018-0156 — Cisco IOS Software and Cisco IOS XE Software Smart Install Denial-of-Service Vulnerability
• CVE-2018-0155 — Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability
• CVE-2018-0154 — Cisco IOS Software Integrated Services Module for VPN Denial-of-Service Vulnerability
• CVE-2017-6744 — Cisco IOS Software SNMP Remote Code Execution Vulnerability
• CVE-2017-6743 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability
• CVE-2017-6740 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability
• CVE-2017-6739 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability
• CVE-2017-6738 — Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability

Latest Cisco IOS vulnerabilities

• CVE-2026-20301 — Cisco IOS Software and IOS XE Software Extensible Messaging Client Protocol Denial of Service Vulnerability (CVSS 8.6)
• CVE-2026-20125 — (CVSS 7.7)
• CVE-2026-20012 — (CVSS 8.6)
• CVE-2025-20363 — (CVSS 9.0)
• CVE-2025-20352 — Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability (CVSS 7.7) — exploited
• CVE-2025-20327 — (CVSS 7.7)
• CVE-2025-20160 — (CVSS 8.1)
• CVE-2025-20149 — (CVSS 6.5)
• CVE-2025-20239 — (CVSS 8.6)
• CVE-2025-20225 — (CVSS 5.8)
• CVE-2025-20181 — (CVSS 6.8)
• CVE-2025-20164 — (CVSS 8.3)
• CVE-2025-20154 — Cisco IOS, IOS XE and IOS XR Software TWAMP Denial of Service Vulnerability (CVSS 8.6)
• CVE-2025-20137 — (CVSS 4.7)
• CVE-2025-20176 — (CVSS 7.7)
• CVE-2025-20175 — (CVSS 7.7)
• CVE-2025-20174 — (CVSS 7.7)
• CVE-2025-20173 — (CVSS 7.7)
• CVE-2025-20172 — (CVSS 7.7)
• CVE-2025-20171 — (CVSS 7.7)
• CVE-2025-20170 — (CVSS 7.7)
• CVE-2025-20169 — (CVSS 7.7)
• CVE-2024-20465 — (CVSS 5.8)
• CVE-2024-20433 — (CVSS 7.5)
• CVE-2024-20414 — (CVSS 6.5)