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Vulnerability record · CVE-2026-5749 · published 22 April 2026

CVE-2026-5749: Missing authentication for critical function vulnerability

Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API.

8.7 CVSS 4.0 High EPSS 0.42% · top 66.4% CWE-306 · Missing authentication for critical function Deferred
8.7CVSS 4.0 base score
0.42%EPSS exploitation probability, 30 days
NoNot in CISA KEV
0Affected product versions listed by NVD
1References
17 Jun 2026Last modified by NVD

Description

Inadequate access control in the registration process in Fullstep V5, which could allow unauthenticated users to obtain a valid JWT token with which to interact with authenticated API resources. Successful exploitation of this vulnerability could allow an unauthenticated attacker to compromise the confidentiality of the affected resource, provided they have a valid token with which to interact with the API.

CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/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://www.incibe.es/en/incibe-cert/notices/aviso/multiple-vulnerabilities-fullstep

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Source: NIST National Vulnerability Database (record CVE-2026-5749), CISA KEV, FIRST EPSS (scores of 2026-09-26). This page is refreshed as NVD updates the record.