WESTERN DIGITAL CORP

Insider Trading Arrangements

During the quarter ended October 2, 2026, the following director and officers (as defined in Rule 16a-1(f) of the Exchange Act) adopted, modified or terminated a trading arrangement for the purchase or sale of securities of Western Digital that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c) of the Exchange Act (“Rule 10b5-1 Plan”):

•On August 7, 2026, Brian Scott Davis, Executive Vice President and Chief Sales and Marketing Officer of the Company, terminated his previously reported Rule 10b5-1 Plans adopted on November 3, 2025 and June 5, 2026. The November 3, 2025 plan was scheduled to expire on August 14, 2026, and the June 5, 2026 plan was scheduled to commence on November 9, 2026.

•On August 14, 2026, Irving Tan, Chief Executive Officer of the Company, modified his previously reported Rule 10b5-1 Plan adopted on February 5, 2026. Mr. Tan’s plan was modified to amend the equity awards subject to the plan, with no change to the expiration date of the plan (May 31, 2027) or the total number of shares subject to the plan (up to an aggregate of 80,000 shares of the Company’s common stock, of which,20,000 shares had already been sold prior to the plan amendment). Trades under the modified plan are subject to a cooling off period consistent with SEC requirements.

•On September 1, 2026, Tunç Doluca, adirector of the Company, adopted a Rule 10b5-1 Plan. Under this plan, up to an aggregate of 13,440 shares of the Company’s common stock may be sold before the plan expires on December 31, 2027.