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Critical VDE-2026-031 1 CVE

WAGO: Early-Boot Diagnostic Exposure in WAGO System I/O Field Devices

Published Jul 13, 2026 · Updated Jul 13, 2026

Vendor: WAGO Product: 0765-110x/0100-0000 Product: 0765-120x/0100-0000 Product: 0765-150x/0100-0000 Product: 0765-2101/0100-0000 Product: 0765-2102/0100-0000 Product: 0765-410x/0100-0000 Product: 0765-420x/0100-0000 Product: 0765-450x/0100-0000

Summary

Certain devices in the WAGO System I/O Field series enable an internal diagnostic capability during the initial stages of system startup. This behavior, which is not part of the publicly documented feature set, briefly allows access to system functions before the main operating environment becomes fully active. Under specific conditions, this could permit interactions with system components that are normally protected during regular operation.

Details

Impact
If network access is available during the early startup phase, an external party may be able to influence device behavior in ways not intended for routine operation. This could potentially affect system integrity or configuration prior to the full initialization of security mechanisms.

Remediation
Update to the listed fixed versions of the affected firmwares:

| Fixed Version | Product Name |
| ------------- | ------------------------------------ |
| 1.2.1.100 | I/O System Field 0765-110x/0100-0000 |
| 1.2.7.100 | I/O System Field 0765-120x/0100-0000 |
| 1.2.7.103 | I/O System Field 0765-150x/0100-0000 |
| 1.2.1.102 | I/O System Field 0765-2101/0100-0000 |
| 1.2.5.101 | I/O System Field 0765-2102/0100-0000 |
| 1.2.1.100 | I/O System Field 0765-410x/0100-0000 |
| 1.2.7.100 | I/O System Field 0765-420x/0100-0000 |
| 1.2.7.103 | I/O System Field 0765-450x/0100-0000 |

Vulnerabilities 1

  • Critical 9.8
    CVE-2026-4769

    Unauthenticated Access to Internal Diagnostic Interface

    Certain devices in the WAGO System I/O Field series activate an internal diagnostic capability during the initial startup sequence. This functionality is not formally documented and becomes accessible without authentication for a brief period in the early boo…

    WAGO 0765-410x/0100-0000 0765-450x/0100-0000 0765-110x/0100-0000 ICS / OT

Revision history

  1. #1.0.0

    Release version.

References