CVE-2017-6663: Cisco IOS Software and Cisco IOS XE Software Denial-of-Service Vulnerability
- Is it exploited?
Yes. CISA added it to the Known Exploited Vulnerabilities catalog on 3 Mar 2022, 1,669 days after the CVE record was published.
- How likely is exploitation in the next 30 days?
- 2.1%
EPSS score, percentile 81.8 of all scored records
- How severe?
- 6.5 Medium
CVSS v3.1 base score, from CISA's enrichment of the record
- What should I do?
CISA deadline 24 Mar 2022. Apply updates per vendor instructions.
The CVE record links no vendor advisory, patch or mitigation.
- Which versions are affected?
Affected
- Cisco IOS and IOS XE
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
What to do
Required action, set by CISA
Apply updates per vendor instructions.
CISA due date for this action: 24 March 2022.
Advisories and patches
The CVE record links no vendor advisory, patch or mitigation.
Linked from CISA's catalog entry
Affected products and versions
As listed in the CVE record.
| Status | Versions |
|---|---|
| Affected | Cisco IOS and IOS XE |
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
About this vulnerability
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting in denial-of-service (DoS).
Summary: CISA's KEV catalog, as of 28 Oct 2026.
- CISA added CVE-2017-6663 to its Known Exploited Vulnerabilities (KEV) catalog on 3 Mar 2022.
- CISA's ransomware flag for this entry is "Unknown": no evidence of ransomware use in the catalog, which is not proof of none.
- The due date CISA sets for the required action is 24 Mar 2022.
- The CVE record was published on 7 Aug 2017, 1,669 days before it was added to KEV.
- The CVE record carries a CVSS v3.1 base score of 6.5 (Medium), taken from CISA's enrichment of the record.
- FIRST's EPSS model puts the probability of exploitation in the next 30 days at 2.1% (percentile 81.8), as of 28 Oct 2026.
- CISA's SSVC assessment in the CVE record: exploitation active, automatable no, technical impact partial.
Source: CISA Known Exploited Vulnerabilities (KEV) catalog, 2026.10.28, as of 28 Oct 2026; CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026; FIRST Exploit Prediction Scoring System (EPSS), v2026.06.15, as of 28 Oct 2026. About the data.
Description
A vulnerability in the Autonomic Networking feature of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, adjacent attacker to cause autonomic nodes of an affected system to reload, resulting in a denial of service (DoS) condition. More Information: CSCvd88936. Known Affected Releases: Denali-16.2.1 Denali-16.3.1.
Source: CVE List V5 (CVE Program), cve_2026-10-28_0000Z, as of 28 Oct 2026. About the data.
Timeline
| Date | Event |
|---|---|
| 7 Aug 2017 | CVE record published |
| 3 Mar 2022 | Added to CISA KEV |
| 24 Mar 2022 | CISA due date for the required action |
| 21 Oct 2025 | CVE record last updated |
References
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