Siemens SIMATIC WinCC NTLM Relay Auth Bypass (All versions)
CVE-2026-58114 Published on November 10, 2026

A vulnerability has been identified in SIMATIC BATCH V9.1 (All versions), SIMATIC Information Server 2020 (All versions), SIMATIC Information Server 2022 (All versions), SIMATIC PCS 7 V9.1 (All versions), SIMATIC Process Historian 2020 (All versions), SIMATIC Process Historian 2022 (All versions), SIMATIC WinCC Runtime Professional V17 (All versions), SIMATIC WinCC Runtime Professional V18 (All versions), SIMATIC WinCC Runtime Professional V19 (All versions), SIMATIC WinCC Runtime Professional V20 (All versions), SIMATIC WinCC Runtime Professional V21 (All versions), SIMATIC WinCC V7.5 (All versions), SIMATIC WinCC V8.0 (All versions), SIMATIC WinCC V8.1 (All versions). Affected systems do not properly secure their remote user authentication with the deprecated NTLM protocol. This could allow unauthenticated remote attackers, who have achieved a machine in the middle position, to relay NTLM authentication and impersonate a legitimate user. The potential impact depends on the services that are accessible, e.g. a SQL server used by WinCC.

NVD

Weakness Type

CWE-1390

Products Associated with CVE-2026-58114

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Affected Versions

Siemens SIMATIC BATCH V9.1: Siemens SIMATIC Information Server 2020: Siemens SIMATIC Information Server 2022: Siemens SIMATIC PCS 7 V9.1: Siemens SIMATIC Process Historian 2020: Siemens SIMATIC Process Historian 2022: Siemens SIMATIC WinCC Runtime Professional V17: Siemens SIMATIC WinCC Runtime Professional V18: Siemens SIMATIC WinCC Runtime Professional V19: Siemens SIMATIC WinCC Runtime Professional V20: Siemens SIMATIC WinCC Runtime Professional V21: Siemens SIMATIC WinCC V7.5: Siemens SIMATIC WinCC V8.0: Siemens SIMATIC WinCC V8.1: