# CVE-2026-5269: Navigator NCS and MCP System Accounts with Default Passwords

> Hidden system accounts with predictable default passwords in Ciena Navigator NCS and MCP allow attackers to potentially escalate privileges when combined with other weaknesses.

- **Severity:** Critical 9.8 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 14 Jul 2026
- **Updated:** 15 Jul 2026
- **Also known as:** GHSA-6jrj-gphg-p8mj

## What is CVE-2026-5269?

CVE-2026-5269 is a critical vulnerability in CIENA MCP, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official 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.

Weakness: CWE-1393 (Use of Default Password)

## Which versions are affected by CVE-2026-5269?


## How do I fix CVE-2026-5269?

No fix has been published for CVE-2026-5269 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-5269 being exploited?

There is no known exploitation of CVE-2026-5269 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-5269 and fix it if it is affected.

What it is: CVE-2026-5269 is a critical vulnerability in CIENA MCP, published on 14 Jul 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-5269 in the wild and no public exploit code.

Affected product: CIENA MCP. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-5269/ (Markdown: https://insights.sbomify.com/CVE-2026-5269/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-5269
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-5269
- OSV: https://osv.dev/vulnerability/CVE-2026-5269

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-5269/
Summaries are generated and may contain mistakes; the official description above is the record.