How severe is CVE-2026-21409?

CVE-2026-21409 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2026-21409 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2026-21409?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

Does CVE-2026-21409 have an EU (EUVD) identifier?

Yes. CVE-2026-21409 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1780.

When was CVE-2026-21409 published?

CVE-2026-21409 was published on 2026-01-09 and last updated on 2026-06-17.

CVE-2026-21409

CVE-2026-21409 is a medium-severity vulnerability with a CVSS 3.x base score of 5.9. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-639.

Key facts

Severity: Medium (CVSS 3.x base score 5.9)
CVSS v4: 8.2
EPSS exploit prediction: 0% (25th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-1780
Weakness: CWE-639
Published: 2026-01-09
Last modified: 2026-06-17

Description

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

Frequently asked questions

What is CVE-2026-21409?: 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 and/or OIDC (OpenID Connect) tokens may be retrieved.
How severe is CVE-2026-21409?: CVE-2026-21409 has a CVSS 3.x base score of 5.9, rated medium severity. It is exploitable over network with high attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2026-21409 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (25th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-21409?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2026-21409 have an EU (EUVD) identifier?: Yes. CVE-2026-21409 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-1780.
When was CVE-2026-21409 published?: CVE-2026-21409 was published on 2026-01-09 and last updated on 2026-06-17.

References

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