Auth bypass in Ciena Navigator Ncs

CVE-2026-5267

Ciena Navigator Network Control Suite (NCS) contains an information exposure vulnerability in an event-streaming API that does not properly enforce authentication. An unauthenticated attacker with network access to the affected service could access the event stream and potentially obtain sensitive information.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-5267?
CVE-2026-5267 is a high-severity vulnerability in Ciena Navigator Ncs, classified under Missing Authentication for Critical Function. CVSS score: 7.5/10. Published 2026-09-25.
How severe is CVE-2026-5267?
High severity. CVSS v3 base score is 7.5 out of 10.