Cyber Resilience

CVE-2026-21409

High

Published: 09 January 2026

Published
09 January 2026
Modified
15 April 2026
KEV Added
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Patch
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CVSS Score v4 8.2 CVSS:4.0/AV:N/AC:H/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:X/V:X/RE:X/U:X
EPSS Score 0.0033 24.3th percentile
Risk Priority 55 floored blend · peak EPSS

Summary

CVE-2026-21409 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Jvn (inferred from references). Its CVSS base score is 8.2 (High).

Operationally, ranked at the 24.3th percentile by exploit likelihood (below the median); it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

A01:2025 Broken Access Control

EU & UK References

Vulnerability details

Improper authorization vulnerability exists in RICOH Streamline NX 3.5.1 to 24R3. If a man-in-the-middle attack is conducted on the communication between the affected product and its user, and some crafted request is processed by the product, the user's registration information…

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and/or OIDC (OpenID Connect) tokens may be retrieved.

CWE(s)
CWE-639

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

Jvn
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inferred from references and description; NVD did not file a CPE for this CVE

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References