Siemens SINEC NMS Improper Authentication Privilege Escalation Vulnerability

April 23rd, 2026
ZDI-26-297 ZDI-CAN-28759

CVE ID

CVE-2026-25654

CVSS Score

8.8 AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected Vendors

Siemens

Affected Products

SINEC NMS

Vulnerability Details

This vulnerability allows remote attackers to escalate privileges on affected installations of Siemens SINEC NMS. Authentication is required to exploit this vulnerability.

The specific flaw exists within the web service, which listens on TCP port 443 by default. The issue results from improper authentication prior to allowing access to functionality. An attacker can leverage this vulnerability to escalate privileges to resources normally protected from the user.

Additional Details

Siemens has issued an update to correct this vulnerability. More details can be found at:
https://cert-portal.siemens.com/productcert/html/ssa-605717.html

Disclosure Timeline

  • 2026-01-22 - Vulnerability reported to vendor
  • 2026-04-23 - Coordinated public release of advisory
  • 2026-04-23 - Advisory Updated

Credit

Rocco Calvi (@TecR0c) with TecSecurity

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