ACTIVELY EXPLOITED
CVE-2018-0173: Cisco IOS and IOS XE Software Improper Input Validation Vulnerability
| Vendor | Cisco |
|---|---|
| Product | IOS and IOS XE Software |
| Actively exploited | Yes |
| Added to CISA KEV | 3 Mar 2022 |
| CISA federal deadline | 17 Mar 2022 |
| Weakness (CWE) | CWE-20 |
Required action (CISA's text)
Apply updates per vendor instructions.
Description (NVD)
A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets can allow for denial-of-service (DoS).
SOURCES
Other Cisco flaws
- CVE-2026-20320: Cisco BroadWorks Improper Restriction of XML External Entity Reference Vulnerability
- CVE-2026-76418: Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability
- CVE-2026-76519: Cisco Secure Email Gateway Relative Path Traversal Vulnerability
- CVE-2026-76504: Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability
- CVE-2026-76460: Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability
Data from NVD, CISA KEV, FIRST EPSS and vendor advisories. Updated 10 Nov 2026.