Is CVE-2019-12666 being actively exploited?

CVE-2019-12666 is not currently listed in the CISA Known Exploited Vulnerabilities (KEV) catalog.

What is the CVSS score for CVE-2019-12666?

CVE-2019-12666 has a CVSS 3.1 base score of 6.7 (MEDIUM).

CVE-2019-12666

MEDIUM · CVSS 6.7EPSS 1.1%EU EUVD

A vulnerability in the Guest Shell of Cisco IOS XE Software could allow an authenticated, local attacker to perform directory traversal on the base Linux operating system of Cisco IOS XE Software. The vulnerability is due to incomplete validation of certain commands. An attacker could exploit this vulnerability by first accessing the Guest Shell and then entering specific commands. A successful exploit could allow the attacker to execute arbitrary code on the base Linux operating system.

Key facts

CVSS score: 6.7 (v3.1)
Severity: MEDIUM
CVSS vector: CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE): CWE-22
EPSS score: 1.1% (66th percentile)
In CISA KEV: No
In EU EUVD: Yes (EUVD-2019-4257)
Published: September 25, 2019
NVD last modified: June 17, 2026
Status: Modified

EU Vulnerability Database (EUVD)

This vulnerability is also tracked by ENISA as EUVD-2019-4257 in the EU Vulnerability Database. Last updated in EUVD on November 20, 2024.

View on the EU Vulnerability Database

Affected products

cisco / ios xe
cisco / ios xe

Certified products that may be affected

5 FIPS 140 or Common Criteria certified products, from automated matching by sec-certs.org.

Cisco ASR 900 Series and NCS4200 Series running IOS-XE 16.9 - Cisco Systems, Inc. - Common Criteria IC3S/MUM01/CISCO/cPP/0119/0016 - archived
Cisco Catalyst 9200L and 9400 Series Switches running IOS-XE 16.9 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-10972-2019 - archived
Cisco Aggregation Services Router 1004 (ASR1K) running IOS-XE 16.9 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-10950-2019 - archived
Cisco Catalyst 3650 and 3850 Series Switches running IOS-XE 16.9 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-10940-2019 - archived
Cisco Catalyst 9400 Series Switches running IOS-XE 16.6 - Cisco Systems, Inc. - Common Criteria CCEVS-VR-VID-10863-2018 - archived

References

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190925-dt(Vendor Advisory)

Last updated September 17, 2026 · Source: NVD, CISA KEV, FIRST.org EPSS

Query CVEs from your AI assistant

The CVE/NVD Explorer brain answers CVE questions directly inside Claude, ChatGPT, or any MCP assistant — always up to date, no setup. Add it once and stop pasting advisories into chat.

Add the CVE brain