CVE-2026-5268

CIENA 6500 S-SeriesVulnerabilityCVSS 9.1

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.

No public exploitation has been reported so far. No distribution fix is listed yet; apply vendor mitigations and monitor.

Recommended action: Track your distribution's security tracker and apply the fix as soon as it ships.

CVE-2026-5268 CIENA 6500 S-Series Vulnerability

Severity metrics

CVSS 3.1 : 9.1 CRITICAL

Attack vectorNetwork (remote)

Attack complexityLow

Privileges requiredNone

User interactionNone

ScopeUnchanged

Confidentiality impactHigh

Integrity impactHigh

Availability impactNone

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

Affected & fixed versions by distribution

Versions are the native distribution strings (backport-aware): RHEL/Debian/SUSE backport fixes, so compare with the distro version comparator (dpkg / rpm / vercmp), not the upstream version.

No affected package in the tracked watchlist yet (Debian, Ubuntu, Arch, SUSE, Red Hat...). Triage may still be pending.

Sources

Advisory NVD CVE.org

Published 2026-07-06 · updated 2026-07-25 · source: NVD