Ciena

=== SEC Form 4 — Statement of Changes in Beneficial Ownership === Document Type: 4 Period of Report: 2026-09-20 10b5-1 Pre-arranged Plan: No --- Issuer --- Name: CIENA CORP (CIEN) CIK: 0000936395 --- Reporting Owner --- Name: Graff Marc D. CIK: 0002080157 Role: Officer (EVP & Chief Financial Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -286 | Price: $348.80 Total Value: $99,756.80 Shares Owned After: 107,233 | Ownership: D (Direct) Footnotes: [F1] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/16/2025. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/18/2025. [F2] Shares reported include unvested Restricted Stock Units (RSUs). --- Footnotes (Complete Index) --- F1: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/16/2025. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/18/2025. F2: Shares reported include unvested Restricted Stock Units (RSUs). --- Signature --- /s/ By: Michelle Rankin For: Marc D Graff (2026-09-21)