CVE-2026-5269 (CVSS 9.8)

Description

In Ciena's Navigator Network Control Suite (NCS) and Manage Control Plan (MCP), there are hidden system accounts used for internal software operations. Some of these accounts have default passwords that may be predictable. While these accounts have very limited permissions on their own, an attacker could combine an attack using one of these accounts with other potential weaknesses to launch a more significant attack, possibly leading to escalation of privilege on the system.

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CVSS v3.1 Score

9.8

CRITICAL

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS — Exploit Prediction

0.0027

Probability of exploitation

0.19%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-1393 CWE-1393

References

Other References

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

Frequently Asked Questions

What is CVE-2026-5269? +

In Ciena's Navigator Network Control Suite (NCS) and Manage Control Plan (MCP), there are hidden system accounts used for internal software operations. Some of these accounts have default passwords that may be predictable. While these accounts have very limited permissions on their own, an attacker could combine an attack using one of these accounts with other potential weaknesses to launch a more significant attack, possibly leading to escalation of privilege on the system. It has a CVSS v3.1 base score of 9.8 (CRITICAL).

How severe is CVE-2026-5269? +

CVE-2026-5269 has a CVSS v3.1 score of 9.8 out of 10, rated CRITICAL. This is a critical vulnerability that should be patched immediately. The EPSS score is 0.0027, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-5269? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

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CVE-2026-5269