CVE-2026-62646Network attack vector

Authentication bypass via predictable session identifiers

Published Sep 8, 2026 · Updated Sep 10, 2026

Insufficient entropy in Siemens Reyrolle 7SR5 before 2.70 allows remote attackers to bypass authentication using predicted session IDs. The session identifier generator produces low-entropy tokens that can be predicted or brute-forced within a feasible number of attempts. No authentication or user interaction is required, and successful token derivation grants access with the impersonated user's privileges.

CVSS severity7.4
High
EPSS probability0.32%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Insufficient entropy in Siemens Reyrolle 7SR5 before 2.70 allows remote attackers to bypass authentication using predicted session IDs. The session identifier generator produces low-entropy tokens that can be predicted or brute-forced within a feasible number of attempts. No authentication or user interaction is required, and successful token derivation grants access with the impersonated user's privileges.

The record

CVE
CVE-2026-62646
Published
Sep 8, 2026
Updated
Sep 10, 2026
Vendor
Siemens AG
Product
Reyrolle 7SR5
Classifications
CWE-331, CAPEC-59, T1078
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 8, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 10, 2026Record 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 <V2.70

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Siemens AG · Reyrolle 7SR5version=0 <V2.70

Published CVSS scores

9.1Siemens ProductCERTCVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N
7.4Siemens ProductCERTCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A: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-331Insufficient Entropy
CAPEC-59Session Credential Falsification through Prediction
T1078Valid Accounts

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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