CVE-2018-0174
Cisco IOS Software and Cisco IOS XE Software Improper Input Validation Vulnerability is confirmed as actively exploited and is listed in the CISA KEV catalog.
Required action
Apply updates per vendor instructions.
CISA notes
https://nvd.nist.gov/vuln/detail/CVE-2018-0174
Description
A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuh91645.
Severity
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HExploitation Context
as of October 14, 2026- CISA added CVE-2018-0174 to the KEV catalog 1,436 days after its CVE record was published.
- It is one of 100 Cisco entries in the CISA KEV catalog, and one of 50 added in 2022.
- Its current EPSS score (7.6%) is higher than that of 23% of CISA KEV entries.
Affected Products
| Vendor | Product | Affected versions |
|---|---|---|
| - | Cisco IOS and IOS XE | Cisco IOS and IOS XE |
References
6 LinksRecord Details
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Tool categories
CVE record data © The MITRE Corporation, used under the CVE Terms of Use. Exploited-in-the-wild data from the CISA Known Exploited Vulnerabilities catalog (CC0). Exploit prediction scores by FIRST EPSS (first.org/epss). This site is not endorsed or certified by MITRE, NVD, CISA, or FIRST.