Ciena 6500 S-Series: authentication bypass

Critical9.1CVE-2026-5268 · Published Jul 6, 2026 · updated Jul 8, 2026

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.