How severe is CVE-2025-20126?

CVE-2025-20126 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.

Is CVE-2025-20126 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2025-20126?

CVE-2025-20126 affects Cisco Thousandeyes Endpoint Agent. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2025-20126?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2025-20126 have an EU (EUVD) identifier?

Yes. CVE-2025-20126 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2154.

When was CVE-2025-20126 published?

CVE-2025-20126 was published on 2025-01-08 and last updated on 2026-06-17.

CVE-2025-20126

CVE-2025-20126 is a medium-severity vulnerability in Cisco Thousandeyes Endpoint Agent with a CVSS 3.x base score of 4.8. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-295.

Key facts

Severity: Medium (CVSS 3.x base score 4.8)
EPSS exploit prediction: 0% (6th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-2154
Weakness: CWE-295
Affected product: Cisco Thousandeyes Endpoint Agent
Published: 2025-01-08
Last modified: 2026-06-17

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.

Frequently asked questions

What is CVE-2025-20126?: 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.
How severe is CVE-2025-20126?: CVE-2025-20126 has a CVSS 3.x base score of 4.8, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity low, and availability none.
Is CVE-2025-20126 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (6th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-20126?: CVE-2025-20126 affects Cisco Thousandeyes Endpoint Agent. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-20126?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-20126 have an EU (EUVD) identifier?: Yes. CVE-2025-20126 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-2154.
When was CVE-2025-20126 published?: CVE-2025-20126 was published on 2025-01-08 and last updated on 2026-06-17.

References

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

Affected products (1)

cpe:2.3:a:cisco:thousandeyes_endpoint_agent:*:*:*:*:*:*:*:*

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