CVE-2026-20199

MEDIUM
Published May 20, 2026 Modified May 20, 2026 CWE-74

Description

A vulnerability in the SSL certificate handling of Cisco ThousandEyes Virtual Appliance could allow an authenticated, remote attacker to execute commands on the underlying operating system as the root user. This vulnerability is due to insufficient validation of user-supplied input. An authenticated attacker could exploit this vulnerability by uploading a crafted certificate to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system. To exploit this vulnerability, the attacker must have valid administrative credentials.

CVSS v3.1 Score

4.7
MEDIUM
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:L/I:L/A:L

EPSS — Exploit Prediction

0.0004
Probability of exploitation
0.13%
Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-74 CWE-74

References

Frequently Asked Questions

What is CVE-2026-20199? +
A vulnerability in the SSL certificate handling of Cisco ThousandEyes Virtual Appliance could allow an authenticated, remote attacker to execute commands on the underlying operating system as the root user. This vulnerability is due to insufficient validation of user-supplied input. An authenticated attacker could exploit this vulnerability by uploading a crafted certificate to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system. To exploit this vulnerability, the attacker must have valid administrative credentials. It has a CVSS v3.1 base score of 4.7 (MEDIUM).
How severe is CVE-2026-20199? +
CVE-2026-20199 has a CVSS v3.1 score of 4.7 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0004, placing it in the 0th percentile for exploitation probability.
How do I check if I'm vulnerable to CVE-2026-20199? +
You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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