WESTERN DIGITAL CORP

Insider Trading Arrangements

Except as described below, during the third quarter, none of our directors or officers (as defined in Rule 16a-1(f) of the Exchange Act)adopted, modified orterminated a trading arrangement for the purchase or sale of securities that was intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) of the Exchange Act (“Rule 10b5-1 Plan”) or constituted a “non-Rule 10b5-1 trading arrangement”:

•Michael Ray, a former Executive Vice President, Chief Legal Officer and Secretary of the Company who left the Company effective January 12, 2024, terminated a Rule 10b5-1 Plan on February 23, 2024.

Additional Guarantors

On April 26, 2024, SanDisk Corporation (“SDC”) and SanDisk Technologies, Inc. (“SDT” and, together with SDC, the “Additional Guarantors”), each wholly-owned subsidiaries of Western Digital Corporation, entered into agreements (the “Additional Guarantees”) to unconditionally guarantee the obligations under the loan agreements governing our revolving credit facility, our Term Loan A-2 maturing 2027, and our Delayed Draw Term Loan (collectively, the “Credit Facilities”), subject to certain exceptions.

As required under the indenture dated as of February 13, 2019 (the “Senior Notes Indenture”) and pursuant to the second supplemental indenture dated as of April 26, 2024, the Additional Guarantors will also guarantee the obligations under our 4.750% Senior Notes due 2026, for so long as and to the extent required under the terms of the Senior Notes Indenture. As required under the indenture dated as of November 3, 2023 (the “Convertible Notes Indenture”) and pursuant to the first supplemental indenture dated as of April 26, 2024, the Additional Guarantors will also guarantee the obligations under our 2028 Convertible Notes, for so long as and to the extent required under the terms of the Convertible Notes Indenture.

In connection with entering into the Additional Guarantees, the Additional Guarantors also entered into agreements to secure the obligations under the Credit Facilities on a first-priority basis (subject to permitted liens) by a lien on substantially all the assets and properties of the Additional Guarantors (the “Additional Collateral”), subject to certain exceptions. The obligations our 2.850% Senior Notes due 2029 and 3.100% Senior Notes due 2032 will be secured by the Additional Collateral on an equal and ratable basis to the obligations under the Credit Facilities for so long as and to the extent required under the terms of the indenture and first supplemental indenture governing such notes.