Cisco ThousandEyes Enterprise Agent SSL Certificate injection

Summaryinfo

A vulnerability was found in Cisco ThousandEyes Enterprise Agent. It has been classified as critical. This impacts an unknown function of the component SSL Certificate Handler. The manipulation leads to injection. This vulnerability is documented as CVE-2026-20199. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Cisco ThousandEyes Enterprise Agent (unknown version) and classified as critical. This issue affects an unknown code block of the component SSL Certificate Handler. The manipulation with an unknown input leads to a injection vulnerability. Using CWE to declare the problem leads to CWE-74. The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component. Impacted is confidentiality, integrity, and availability. The summary by CVE is:

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.

The advisory is shared at sec.cloudapps.cisco.com. The identification of this vulnerability is CVE-2026-20199 since 10/08/2025. The exploitation is known to be easy. The attack may be initiated remotely. The exploitation needs additional levels of successful authentication. Neither technical details nor an exploit are publicly available. The price for an exploit might be around USD $0-$5k at the moment (estimation calculated on 07/23/2026). MITRE ATT&CK project uses the attack technique T1055 for this issue.

Upgrading eliminates this vulnerability.

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Productinfo

Vendor

• Cisco

Name

• ThousandEyes Enterprise Agent

License

• commercial

Website

• Vendor: https://www.cisco.com/

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