Fortinet, Inc.

Rule 10b5-1 Trading Plans

On August 31, 2026, Janet Napolitano, one of our directors, entered into a pre-arranged written stock sale plan in accordance with Rule 10b5-1 under the Exchange Act for the sale of shares of our common stock (the “Napolitano Plan”) during an open trading window in accordance with our insider trading policy. The Napolitano Plan is intended to satisfy the affirmative defense of Rule 10b5-1(c) under the Exchange Act. The Napolitano Plan provides for the potential sale by Ms. Napolitano of up to 390 shares of our common stock, plus up to 60% of the additional net shares (the number of which is not yet determinable) remaining after shares are withheld to satisfy tax obligations upon vesting and settlement of RSUs, in each case, at prices determined in accordance with the terms of the Napolitano Plan, all between November 30, 2026 and December 3, 2027.

The Napolitano Plan includes a representation from Ms. Napolitano to the broker administering the plan that she was not in possession of any material nonpublic information regarding us or the securities subject to the Napolitano Plan at the time that she entered into the Napolitano Plan. She made a similar representation to us in connection with the adoption of the Napolitano Plan under our insider trading policy. The representation was made as of August 31, 2026, and speaks only as of that date. In making the representation, Ms. Napolitano did not provide assurance with respect to any material nonpublic information of which she was unaware, or with respect to any material nonpublic information acquired by her or us after the date of the representation.

Once executed, transactions under the Napolitano Plan will be disclosed publicly through Form 4 and/or Form 144 filings with the SEC in accordance with applicable securities laws, rules and regulations. Except as may be required by law, we do not undertake any obligation to update or report any modification, termination, or other activity under current or future Rule 10b5-1 plans that may be adopted by Ms. Napolitano or our other officers or directors, or their affiliated entities.