Cisco IOS and IOS XE known exploited vulnerabilities
We track 21 CVEs in Cisco IOS and IOS XE. All of them are on CISA's Known Exploited Vulnerabilities catalog, meaning CISA has evidence of exploitation in the wild (listed 2021–2025). The most recent is CVE-2025-20352, added to KEV on .
Also listed as: IOS Software and Cisco IOS XE Software · IOS and IOS XE Software · IOS and IOS XE with Smart Install client enabled. CISA, NVD and vendor advisories name the same product differently; each CVE page keeps the wording from its source.
- CVEs tracked
- 21
- On CISA KEV
- 21
- Ransomware use
- 0
- Rated critical
- 4
Every Cisco IOS and IOS XE CVE we track
| CVE / Vulnerability | Severity | CVSS | EPSS | Added to KEV | Patch by |
|---|---|---|---|---|---|
| CVE-2025-20352 Cisco IOS and IOS XE Software SNMP Denial of Service and Remote Code Execution Vulnerability | [ HIGH ] | 7.7 | 41.5% | ||
| CVE-2023-20109 Cisco IOS and IOS XE Group Encrypted Transport VPN Out-of-Bounds Write Vulnerability | [ MEDIUM ] | 6.6 | 2.5% | ||
| CVE-2017-6742 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 21.4% | ||
| CVE-2017-3881 Cisco IOS and IOS XE Remote Code Execution Vulnerability | [ CRITICAL ] | 9.8 | 99.0% | ||
| CVE-2018-0173 Cisco IOS and IOS XE Software Improper Input Validation Vulnerability | [ HIGH ] | 8.6 | 7.6% | ||
| CVE-2018-0172 Cisco IOS and IOS XE Software Improper Input Validation Vulnerability | [ HIGH ] | 8.6 | 7.8% | ||
| CVE-2018-0159 Cisco IOS and XE Software Internet Key Exchange Version 1 Denial-of-Service Vulnerability | [ HIGH ] | 7.5 | 6.9% | ||
| CVE-2018-0158 Cisco IOS and XE Software Internet Key Exchange Memory Leak Vulnerability | [ HIGH ] | 8.6 | 7.2% | ||
| CVE-2018-0156 Cisco IOS Software and Cisco IOS XE Software Smart Install Denial-of-Service Vulnerability | [ HIGH ] | 7.5 | 9.4% | ||
| CVE-2018-0151 Cisco IOS Software and Cisco IOS XE Software Quality of Service Remote Code Execution Vulnerability | [ CRITICAL ] | 9.8 | 14.2% | ||
| CVE-2017-6743 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 10.9% | ||
| CVE-2017-6740 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 11.1% | ||
| CVE-2017-6739 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 10.9% | ||
| CVE-2017-6738 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 10.9% | ||
| CVE-2017-6737 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 45.2% | ||
| CVE-2017-6736 Cisco IOS and IOS XE Software SNMP Remote Code Execution Vulnerability | [ HIGH ] | 8.8 | 70.4% | ||
| CVE-2017-6663 Cisco IOS Software and Cisco IOS XE Software Denial-of-Service Vulnerability | [ MEDIUM ] | 6.5 | 2.1% | ||
| CVE-2017-6627 Cisco IOS Software and Cisco IOS XE Software UDP Packet Processing Denial-of-Service Vulnerability | [ HIGH ] | 7.5 | 6.2% | ||
| CVE-2017-12240 Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability | [ CRITICAL ] | 9.8 | 13.8% | ||
| CVE-2017-12237 Cisco IOS and IOS XE Software Internet Key Exchange Denial-of-Service Vulnerability | [ HIGH ] | 7.5 | 7.1% | ||
| CVE-2018-0171 Cisco Smart Install unauthenticated RCE in IOS and IOS XEwrite-up | [ CRITICAL ] | 9.8 | 99.5% |
Sorted by date added to KEV. Severity and CVSS as stated by NVD or the vendor; EPSS from FIRST.org. "Patch by" is CISA's BOD 22-01 deadline for US federal agencies, a useful priority signal for everyone else. Machine-readable: /api/v1/vendors/cisco.json.
Our Cisco IOS and IOS XE coverage
Other Cisco products
Every row links to its CVE record with the CISA required action, catalog coverage and primary sources. We describe impact and remediation only; no exploit code. See the full KEV tracker or compare KEV catalogs.