Skip to content

An authentication bypass vulnerability exists in the...

Critical severity Unreviewed Published Jul 6, 2026 to the GitHub Advisory Database • Updated Jul 6, 2026

Package

No package listed— Suggest a package

Affected versions

Unknown

Patched versions

Unknown

Description

An authentication bypass vulnerability exists in
the default SFTP server component utilized across the Ciena products listed. This vulnerability allows a remote, unauthenticated attacker to bypass
security controls and gain unauthorized access to the underlying filesystem.
Successful exploitation could allow an attacker to read or modify system files.

References

Published by the National Vulnerability Database Jul 6, 2026
Published to the GitHub Advisory Database Jul 6, 2026
Last updated Jul 6, 2026

Severity

Critical

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
None

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(49th percentile)

Weaknesses

Authentication Bypass Using an Alternate Path or Channel

The product requires authentication, but the product has an alternate path or channel that does not require authentication. Learn more on MITRE.

CVE ID

CVE-2026-5268

GHSA ID

GHSA-m6c7-7xhp-6vhc

Source code

No known source code

Dependabot alerts are not supported on this advisory because it does not have a package from a supported ecosystem with an affected and fixed version.

Learn more about GitHub language support

Loading Checking history
See something to contribute? Suggest improvements for this vulnerability.