CVE-2026-5270

CRITICALPre-NVD 9.8Trending — 3 sources updated this week
9.8
EchelonGraph verdictPlan a fixSerious severity, but no confirmed exploitation yet.
  • High severity, but no confirmed exploitation yet
CISA-KEV: Not listedEPSS: —CVSS: 9.8Exploit: NoneExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

An authentication bypass vulnerability exists in certain releases of Ciena Navigator Network Control Suite (NCS), Manage Control Plan (MCP), and Blue Planet products. The issue is caused by improper handling of HTTP request paths and headers, which allows an unauthenticated attacker to manipulate requests in a manner that bypasses authentication and associated audit logging controls.

CVSS v3
9.8
EG Score
0.0(none)
EPSS
—
KEV
Not listed

Published

July 14, 2026

Last Modified

July 15, 2026

References (1)

Vendor Advisories for CVE-2026-5270(1)

These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 4× in last 7d / 4× in last 30d)

Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.

  1. 2026-07-15 12:54 UTCMITRE cvelistV5CVSS v3 → 9.8 · severity → CRITICAL
  2. 2026-07-14 23:23 UTCNVD update
  3. 2026-07-14 22:46 UTCEG score recompute
  4. 2026-07-14 22:45 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(4)

What is CVE-2026-5270?
CVE-2026-5270 is a critical vulnerability published on July 14, 2026. An authentication bypass vulnerability exists in certain releases of Ciena Navigator Network Control Suite (NCS), Manage Control Plan (MCP), and Blue Planet products. The issue is caused by improper handling of HTTP request paths and headers, which allows an unauthenticated attacker to manipulate…
When was CVE-2026-5270 disclosed?
CVE-2026-5270 was first published in the National Vulnerability Database on July 14, 2026, with the most recent update on July 15, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
What is the CVSS score of CVE-2026-5270?
CVE-2026-5270 has a CVSS v3.1 base score of 9.8 (CISA-ADP / Vulnrichment enrichment; NVD's own analysis pending). EchelonGraph synthesises NVD + CISA KEV + FIRST EPSS + GHSA into a combined EG score of 0.0.
How do I remediate CVE-2026-5270?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-5270, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.

Dependency Blast Radius

Explore the affected products and dependency analysis for CVE-2026-5270

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