CVE-2025-40736Network attack vector

Authentication bypass via unguarded password-change method

Published Jul 8, 2025 · Updated Jul 8, 2025

Authentication bypass in Siemens SINEC NMS before 4.0 allows remote attackers to reset the superadmin password through an exposed endpoint. The reqToChangePassword method exposes password-change functionality without authenticating the request before modifying administrative credentials. No account or user interaction is required, and a successful reset grants full control of the application.

CVSS severity9.8
Critical
EPSS probability0.40%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Authentication bypass in Siemens SINEC NMS before 4.0 allows remote attackers to reset the superadmin password through an exposed endpoint. The reqToChangePassword method exposes password-change functionality without authenticating the request before modifying administrative credentials. No account or user interaction is required, and a successful reset grants full control of the application.

The record

CVE
CVE-2025-40736
Published
Jul 8, 2025
Updated
Jul 8, 2025
Vendor
Siemens
Product
SINEC NMS
Classifications
CWE-306, T1098
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jul 8, 2025CVE publishedPublication date reported by the CVE source.
  2. Jul 8, 2025Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <V4.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens · SINEC NMSversion=0 <V4.0

Published CVSS scores

9.8Siemens AGCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
9.3Siemens AGCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-306Missing Authentication for Critical Function
T1098Account Manipulation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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