CVE-2026-5267: Unauthenticated Event Stream Exposure of Session Tokens in Navigator NCS

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.4% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-09-25 · updated 2026-09-28
Weakness: CWE-306

Description

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.

Affected products

CIENA Navigator NCS: from 7.2-P01 through 7.2-P07; from 8.0-P01 through 8.0-P06A; from 8.1-P01 through 8.1-P06; from 8.2-P01 through 8.2-P06; from 9.0-P01 through 9.0-P05A; from 9.1-P01 through 9.1-P05

References

https://www.ciena.com/product-security

Get alerted when CVE-2026-5267 or the next vulnerability affects your stack