COMMVAULT SYSTEMS INC

Fifth Amended and Restated Bylaws

On May 7, 2026, the Board of Directors adopted the Fifth Amended and Restated Bylaws of the Company (the "Fifth A&R Bylaws"), effective immediately. The amendments (i) change the timing requirement for submitting notice of director nominations and business proposals from a deadline of 90 days before the anniversary date of the prior year’s annual meeting of stockholders to a window of 90-120 days prior thereto, (ii) revise the advance notice provisions related to submission of director nominations and business proposals at annual meetings of stockholders of the Company, including updating other timing, procedural and informational requirements and reflecting the universal proxy rules under Rule 14a-19 of the Securities Exchange Act of 1934, as amended, (iii) update provisions relating to the procedure for calling special meetings of the Board of Directors, (iv) authorize stockholder and Board meetings by means of remote communications, (v) clarify the powers of the chair of a meeting of stockholders to regulate conduct at and to adjourn such meeting; and (vi) make certain other technical, conforming, modernizing and clarifying changes.

The foregoing description of the Fifth A&R Bylaws does not purport to be complete and is qualified in its entirety by reference to the full text of the Fifth A&R Bylaws, which is filed as Exhibit 3.4 to this Annual Report on Form 10-K and incorporated herein by reference.

Rule 10b5-1 Insider Trading Arrangements

On February 3, 2026, Vivie Lee, amember of our Board of Directors, adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of 595 shares of the Company’s common stock. The plan is in effect until the earlier of February 3, 2027 or the completion of all authorized sales.

On February 17, 2026, Danielle Abrahamsen, Chief Accounting Officer, adopted a Rule 10b5-1 trading arrangement intended to satisfy the affirmative defense of Rule 10b5-1(c) for the sale of up to approximately 6,600 shares of the Company’s common stock. Actual sales will vary due to the achievement of PSUs and shares sold for tax obligations. The plan is in effect until the earlier of February 10, 2027 or the completion of all authorized sales.

During the three months ended March 31, 2026, no other directors or officers of the Company adopted, modified orterminated any Rule 10b5-1 trading arrangement or "Non-Rule 10b5-1 trading arrangement" as each term is defined in Item 408 of Regulation S-K.