SCHEDULE 13D/A 0001260943 XXXXXXXX LIVE 4 Common Stock, par value $0.0001 03/23/2025 false 0001799208 26484T106 Dun & Bradstreet Holdings, Inc.

5335 Gate Parkway Jacksonville FL 32256

Shari Wolkon General Counsel (617) 227-1050 Thomas H. Lee Partners, L.P. 100 Federal Street, 36th Floor Boston MA 02110 0001260943 THOMAS H. LEE ADVISORS, LLC b OO DE 0 22525103 0 22525103 22525103 N 5.1 OO Y Thomas H. Lee Equity Fund VIII, L.P. b OO DE 0 6142612 0 6142612 6142612 N 1.4 PN Y Thomas H. Lee Parallel Fund VIII, L.P. b OO DE 0 11184899 0 11184899 11184899 N 2.5 PN Y THL Executive Fund VIII, L.P. b OO DE 0 468969 0 468969 468969 N 0.1 PN Y THL Equity Advisors VIII, LLC b OO DE 0 22525103 0 22525103 22525103 N 5.1 OO Y Thomas H. Lee Partners, L.P. b OO DE 0 22525103 0 22525103 22525103 N 5.1 PN Y THL Managers VIII, LLC b OO DE 58210 22525103 58210 22525103 22583313 N 5.1 OO Y THL Holdco, LLC b OO DE 0 22525103 0 22525103 22525103 N 5.1 OO Y THL Fund VIII Coinvestment Partners, L.P. b OO DE 0 730006 0 730006 730006 N 0.2 PN Y THL Equity Fund VIII Investors (D&B), L.P. b OO DE 0 3998617 0 3998617 3998617 N 0.9 PN Common Stock, par value $0.0001 Dun & Bradstreet Holdings, Inc. 5335 Gate Parkway Jacksonville FL 32256 This Amendment No. 4 ("Amendment No. 4") amends and supplements the statement on Schedule 13D originally filed by the Reporting Persons on February 25, 2022 (as amended from time to time, the "Schedule 13D"). Except as specifically provided herein, this Amendment No. 4 does not modify any of the information previously reported in the Schedule 13D. Unless otherwise indicated, each capitalized term used but not defined in this Amendment No. 4 shall have the meaning assigned to such term in the Schedule 13D. Item 4 of the Schedule 13D is supplemented as follows: The information provided in Item 6 is incorporated herein by reference. Item 5(a) of the Schedule 13D is supplemented as follows: The percentage of beneficial ownership in this Amendment No. 4 is based on 441,516,369 shares of Common Stock outstanding as of February 14, 2025, as reported in the Issuer's Annual Report on Form 10-K for the year ended December 31, 2024, filed with the Securities and Exchange Commission (the "SEC") on February 21, 2025. Item 5(b) of the Schedule 13D is supplemented as follows: The aggregate number of shares of Common Stock beneficially owned by each Reporting Person and, for each Reporting Person, the number of shares as to which there is sole power to vote or to direct the vote, shared power to vote or to direct the vote, sole power to dispose or to direct the disposition, or shared power to dispose or to direct the disposition are set forth on rows 7 through 11 and row 13 of the cover pages of this Amendment No. 4 and are incorporated herein by reference. Item 5(c) of the Schedule 13D is supplemented as follows: No transactions with respect to the shares of Common Stock were effected during the past sixty days by any of the Reporting Persons. Not applicable. Not applicable. Item 6 of the Schedule 13D is supplemented as follows: On March 23, 2025, the Issuer entered into an Agreement and Plan of Merger (the "Merger Agreement") with Denali Intermediate Holdings, Inc., and Denali Buyer, Inc., whereby,subject to the terms thereof, Denali Buyer, Inc. will merge with and the Issuer (the "Merger"), with the Issuer surviving the Merger as a direct wholly owned subsidiary of Denali Intermediate Holdings, Inc. Concurrently with the execution of the Merger Agreement, on March 23, 2025, each of Thomas H. Lee Equity Fund VIII, L.P., Thomas H. Lee Parallel Fund VIII, L.P., THL Executive Fund VIII, L.P., THL Fund VIII Coinvestment Partners, L.P., THL Equity Fund VIII Investors (D&B), L.P. and THL Managers VIII, L.P. (together, the "Supporting Stockholders") entered into a Voting and Support Agreement (the "Voting and Support Agreement") with the Issuer and Denali Intermediate Holdings, Inc., with respect to Shares owned of record or beneficially by each Supporting Stockholder (collectively, the "Owned Shares"). Pursuant to the Voting and support agreement, among other things,the Supporting Stockholders have agreed to vote all of their Owned Shares in favor of the Merger, the adoption of the Merger Agreement, each of the other actions contemplated by the Merger Agreement or necessary or desirable in furtherance of the Merger and the other transactions contemplated by the Merger Agreement, and against any action or agreement that could reasonably be expected to result in any of the conditions to the consummation of the Merger under the Merger Agreement not being fulfilled. In the event the Issuer's board of directors changes its recommendation that the Company's stockholders vote to adopt the Merger Agreement and approve the Merger, each Supporting Stockholder may vote its shares with respect to the above matters in any manner it chooses. In addition, each Supporting Stockholder has agreed not to take certain actions, including (i) tendering any Owned Shares into any tender or exchange offer, (ii) transferring any Owned Shares (subject to certain exceptions), (iii) granting any proxies or powers of attorney or (iv) taking any action that would make any representation or warranty of such Supporting Stockholder contained in the Voting and Support Agreement untrue or incorrect in any material respect or have the effect of preventing or disabling such Supporting Stockholder from performing its obligations under the Voting and Support Agreement in any material respect. The Voting and Support Agreement will terminate upon the earliest to occur of the Effective Time (as defined in the Merger Agreement) and the valid termination of the Merger Agreement in accordance with its terms. The foregoing description of the Voting and Support Agreement does not purport to be complete and is subject to, and is qualified in its entirety by the terms and conditions of each the Voting and Support Agreement, a copy of which is filed as an exhibit under Item 7 hereto and is incorporated by reference herein, and the foregoing description of the Voting and Support Agreement is qualified in its entirety by reference thereto. Voting Agreement, dated March 23, 2025, by and among Dun & Bradstreet Holdings, Inc., Denali Intermediate Holdings, Inc. and Thomas H. Lee Partners. THOMAS H. LEE ADVISORS, LLC THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 Thomas H. Lee Equity Fund VIII, L.P. THL Equity Advisors VIII, LLC 03/25/2025 Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 Thomas H. Lee Parallel Fund VIII, L.P. THL Equity Advisors VIII, LLC 03/25/2025 Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s Michael McDonnell 03/25/2025 THL Executive Fund VIII, L.P. THL Equity Advisors VIII, LLC 03/25/2025 Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 THL Equity Advisors VIII, LLC Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 Thomas H. Lee Partners, L.P. Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 THL Managers VIII, LLC Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 THL Holdco, LLC /s/ Michael McDonnell 03/25/2025 THL Fund VIII Coinvestment Partners, L.P. Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025 THL Equity Fund VIII Investors (D&B), L.P. THL Equity Advisors VIII 03/25/2025 Thomas H. Lee Partners, L.P. 03/25/2025 Thomas H. Lee Advisors, LLC 03/25/2025 THL Holdco, LLC 03/25/2025 /s/ Michael McDonnell 03/25/2025