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: Kosaraju Sheela CIK: 0001963781 Role: Officer (EVP & Chief Legal Officer) --- Non-Derivative Transactions --- [Transaction #1] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -156 | Price: $348.80 Total Value: $54,412.80 Shares Owned After: 87,925 | 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 12/13/2022. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 3 filed on 2/3/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #2] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -691 | Price: $348.80 Total Value: $241,020.80 Shares Owned After: 87,234 | Ownership: D (Direct) Footnotes: [F3] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 2/1/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 2/3/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #3] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -549 | Price: $348.80 Total Value: $191,491.20 Shares Owned After: 86,685 | Ownership: D (Direct) Footnotes: [F4] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/12/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/14/2023. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #4] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -330 | Price: $348.80 Total Value: $115,104.00 Shares Owned After: 86,355 | Ownership: D (Direct) Footnotes: [F5] Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/17/2024. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/19/2024. [F2] Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). [Transaction #5] Security: Common Stock Date: 2026-09-20 | Code: F (Payment of exercise/tax) Shares: -189 | Price: $348.80 Total Value: $65,923.20 Shares Owned After: 86,166 | Ownership: D (Direct) Footnotes: [F6] 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) and Performance Stock Units (PSUs). --- 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 12/13/2022. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 3 filed on 2/3/2023. F2: Shares reported include unvested Restricted Stock Units (RSUs) and Performance Stock Units (PSUs). F3: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 2/1/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 2/3/2023. F4: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/12/2023. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/14/2023. F5: Represents shares withheld to cover payment of the tax liabilities of the reporting person related to a restricted stock unit (RSU) award agreement dated 12/17/2024. Acquisition of the RSU was previously reported in Table I of the reporting person's Form 4 filed on 12/19/2024. F6: 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. --- Signature --- /s/ By: Michelle Rankin For: Sheela Kosaraju (2026-09-21)