CVE-2025-42611: Improper certificate validation in multiple RouterOS services

Published May 5, 2026
·
Updated

RouterOS provides various services that rely on correct verification of client and server certificates to secure confidentiality and integrity of communications. This includes OpenVPN, CAPsMAN, Dot1x (802.1X), among others.

The vulnerability lies in shared certificate validation logic which uses the system certificate store that is shared and equally trusted by all system services. This causes confusion of scope, allowing any certificate authority present in the system-wide trust store to be trusted in any context (with some exceptions), allowing partial or full authentication bypass in CAPsMAN, OpenVPN, Dot1X and potentially others.

Affected Software

1 affected component
Mikrotik RouterOS

Event History

May 5, 2026
CVE Published
via MITRE·10:58 AM
Data Sourced
via MITRE·10:58 AM
DescriptionSeverityWeakness
Data Sourced
via NVD·11:16 AM
DescriptionSeverityWeakness
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Frequently Asked Questions

1

What is the severity of CVE-2025-42611?

CVE-2025-42611 is classified as a critical vulnerability due to improper certificate validation.

2

How do I fix CVE-2025-42611?

To fix CVE-2025-42611, ensure that you update your MikroTik RouterOS to the latest version where the certificate validation issue has been addressed.

3

What services are affected by CVE-2025-42611?

CVE-2025-42611 affects multiple RouterOS services, including OpenVPN, CAPsMAN, and Dot1x (802.1X), among others.

4

What are the risks associated with CVE-2025-42611?

The risks associated with CVE-2025-42611 include the potential for unauthorized access and interception of secure communications due to improper certificate validation.

5

How can I determine if my RouterOS is vulnerable to CVE-2025-42611?

You can determine if your RouterOS is vulnerable to CVE-2025-42611 by checking if you are using an affected version prior to the patch release mentioned in security advisories.

Contact

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