Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability
Cisco / IOS and IOS XE Software
The Dynamic Host Configuration Protocol (DHCP) relay subsystem of Cisco IOS and Cisco IOS XE Software contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code and gain full control of an affected system.
- CVE identifier
- CVE-2017-12240
- Added to KEV
- Mar 3, 2022
- CISA catalog dueDate
- Mar 24, 2022
The dates above are catalog fields. The addition date does not establish when the vulnerability was discovered or first exploited. Confirm which requirements apply to your organisation separately.
Publisher's required action
Apply updates per vendor instructions.
This wording is attributed to the CISA snapshot. Verify current vendor guidance, affected versions and your deployment before applying changes.
Keep the signals separate.
- Ransomware use, as reported by CISA
- Unknown
- CVSS severity
- Not supplied by KEV
- EPSS probability
- Not available
No EPSS value was supplied for this record in the current snapshot. Unknown values are not treated as zero.
“Unknown” ransomware use is an unknown source field, not proof that ransomware activity has not occurred.
Source notes
https://nvd.nist.gov/vuln/detail/CVE-2017-12240
Source & freshness
Source updated: Nov 6, 2026, 7:44 PM UTC
Successfully checked: Nov 8, 2026, 12:22 AM UTC
This snapshot is older than 36 hours. Check current publisher guidance.
Automated source record, not an editorial advisory or an independent discovery. No affected or fixed version is inferred, and no organisation-specific risk rating is generated.