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Vulnerability record · CVE-2026-56451 · published 14 July 2026

CVE-2026-56451: Improper verification of cryptographic signature vulnerability

A vulnerability has been identified in Opcenter X (All versions < V2604). Affected applications do not properly validate the algorithm specified in the JSON Web Token (JWT) header. This could allow an unauthenticated remote attacker to forge arbitrary JWT, bypass authentication mechanisms and impersonate any user including administrative accounts, potentially gaining full unauthorized access to the application.

10.0 CVSS 4.0 Critical EPSS 0.50% · top 59.8% CWE-347 · Improper verification of cryptographic signature Deferred
10.0CVSS 4.0 base score
0.50%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
1References
15 Jul 2026Last modified by NVD

Description

A vulnerability has been identified in Opcenter X (All versions < V2604). Affected applications do not properly validate the algorithm specified in the JSON Web Token (JWT) header. This could allow an unauthenticated remote attacker to forge arbitrary JWT, bypass authentication mechanisms and impersonate any user including administrative accounts, potentially gaining full unauthorized access to the application.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:L/SC:L/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:

References

LinkTags
https://cert-portal.siemens.com/productcert/html/ssa-096828.html

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Same products first, then exploited flaws of the same weakness class.

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Source: NIST National Vulnerability Database (record CVE-2026-56451), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.