Skip to content
OpenAdvisories
High VDE-2026-077 1 CVE

Lenze: Incorrect signature validation in the enable SSH routine

Published Jul 27, 2026 · Updated Jul 27, 2026

Vendor: Lenze Product: c430 Product: c520 Product: c550 Product: i950 GenA Product: i950 GenB

Summary

The affected products belong to the Controller or Servo Drive product family and contain a vulnerability in a security-critical activation mechanism for service access. The signature verification of a file used for SSH activation can be compromised, which could allow unauthorized access to the device.

Details

Impact
This vulnerability could compromise the confidentiality, integrity, and availability of the product.

Remediation
To resolve this security vulnerability, we recommend installing a firmware update.

| Product | Firmware | Fixed Version |
| --------------- | -------- | ------------- |
| Controller c430 | c4xx | 1.15.2 |
| c520 | c5xx | 1.15.2 |
| c550 | c5xx | 1.15.2 |
| i950 GenA | i950 | 1.15.0 |
| i950 GenB | i950 | 2.0.3 |

Mitigation
Check to see if there is an activation file on the SD Card, and delete it. In addition, it is recommended that you protect each access path with appropriate measures, such as physically securing access to the SD Card, authorizing file transfers via PLC Designer (if supported by the respective product), authorizing file transfers via OPC UA (if supported by the respective product), and customizing the key for SFTP access.

Vulnerabilities 1

  • High 7.8
    CVE-2026-14837

    SSH Enablement Signature Verification Bypass

    Multiple Lenze products are affected by an improper signature verification vulnerability in the SSH enablement mechanism. A low-privileged local attacker can bypass verification of the SSH enable file signature and enable SSH access on the device. Successful …

    Lenze c520 i950 GenA c430

Revision history

  1. #1.0.0

    Initial release.

References