WY: Company disclosure

Item 7.01. Regulation FD Disclosure Item 9.01. Financial Statements and Exhibits Signatures EXHIBIT 99.1 Investor presentation EXHIBIT 104 Cover page interactive data file (embedded within the inline XBRL document) Table of Contents Section 7 – Regulation FD Item 7.01. Regulati on FD Disclosure On September 24, 2026, Weyerhaeuser Company is posting presentation materials to the Investors section of its website that it expects to use in discussions with the investment community. The materials include adjustments and associated commentary to the company's previously disclosed third-quarter 2026 outlook. A copy of the presentation materials is furnished as Exhibit 99.1 to this report. In accordance with General Instruction B.2 of Form 8-K, the information in this Current Report on Form 8-K, including Exhibit 99.1, shall not be deemed to be “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liability of that section, and shall not be incorporated by reference into any registration statement or other document filed under the Securities Act of 1933, as amended, or the Exchange Act, except as shall be expressly set forth by specific reference in such filing. Section 9 - Financial Statements and Exhibits Item 9.01. Financial S tatements and Exhibits (d) Exhibits . Exhibit No. Description 99.1 Investor presentation 104 Cover page interactive data file (embedded within the inline XBRL document). Table of Contents SIGNAT URES Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. WEYERHAEUSER COMPANY By: /s/ Kristy T. Harlan Name: Kristy T. Harlan Its: Senior Vice Presid