CVE-2026-62647

Predictable Session Identifier Generation in Siemens Reyrolle 7SR5 Enables Authentication Impersonation

Published Sep 8, 2026 CVSS 4.0 · 9.3 Critical EPSS < 1% KEV · Not listed
Description
A vulnerability has been identified in Reyrolle 7SR5 (All versions < V2.70). A random number generator is used to generate security-relevant values (such as session identifiers used for authentication purposes) that is not initialized with a True Random Number Generator (TRNG), resulting in a predictable sequence of generated values. This could allow an unauthenticated remote attacker to more easily predict the generated values and impersonate a legitimate authenticated user, potentially gaining unauthorized access to the device.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Siemens
Siemens reyrolle 7sr5
Vendors & Products Siemens
Siemens reyrolle 7sr5
Type Values Removed Values Added
Title Predictable Session Identifier Generation in Siemens Reyrolle 7SR5 Enables Authentication Impersonation
Type Values Removed Values Added
Description A vulnerability has been identified in Reyrolle 7SR5 (All versions < V2.70). A random number generator is used to generate security-relevant values (such as session identifiers used for authentication purposes) that is not initialized with a True Random Number Generator (TRNG), resulting in a predictable sequence of generated values. This could allow an unauthenticated remote attacker to more easily predict the generated values and impersonate a legitimate authenticated user, potentially gaining unauthorized access to the device.
Weaknesses CWE-20
References
Metrics cvssV3_1

{'score': 7.4, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N'}

cvssV4_0

{'score': 9.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
siemens
Published
Updated
Sep 14, 2026, 1:50 PM
Reserved
Jul 14, 2026, 4:24 PM
Status
Deferred
Published
Sep 8, 2026, 9:18 AM
Modified
Sep 14, 2026, 2:17 PM