Cosan S.A.

COSAN S.A. (B3: CSAN3; NYSE: CSAN) (“Cosan” or the “Company”), in compliance with article 157, paragraph 4, of Law No. 6,404, of December 15, 1976, and with Resolution No. 44 of the Brazilian Securities and Exchange Commission (“CVM”), of August 23, 2021, and further to the Material Facts disclosed by the Company on September 21, 2025, October 23, 2025 and on this date, hereby informs its shareholders and the market in general that, on this date, the Company has launched a primary offering of its common shares (“Shares” and “Offering” or “Second Public Offering”, respectively) directed (i) in Brazil, exclusively to professional investors, as defined in Article 11 of CVM Resolution No. 30, dated May 11, 2021, who are resident and domiciled or headquartered in Brazil, pursuant to CVM Resolution No. 160, dated July 13, 2022 (“CVM Resolution 160”), (ii) within the United States, to a limited number of qualified institutional buyers, residents and domiciled in the United States of America, as defined in Rule 144A under the U.S. Securities Act of 1933, as amended, (the “Securities Act”) promulgated by the U.S. Securities and Exchange Commission (“SEC”) pursuant to procedures consistent with, and in reliance on, Section 4(a)(2) of the Securities Act in transactions exempt from, or not subject to, registration under the Securities Act and the rules thereunder, and (iii) outside of the United States and Brazil, to institutional and other investors that are not U.S. persons (as defined in Regulation S of the Securities Act) in reliance on Regulation S under the Securities Act and exemptions from United States securities registration requirements.

The Offering will comprise, initially, the issuance of 187,500,000 Shares by the Company, which number may, at the discretion of the Company, in agreement with the placement agents after the bookbuilding process, be increased by up to 53.33% of the total number of Shares initially offered, or 100,000,000 common shares to be issued by the Company, at the same price as the Shares initially offered, to meet any excess demand that may be identified at the time the price per Share is determined. The Second Public Offering will be carried out at the same price per share as the first public offering that the Company announced in the material fact disclosed on October 23rd, 2025, that is, at a fixed price of R$5.00 per Share, which was ratified at the meeting of the Board of Directors approving such first offering.

THE COMPANY WILL NOT MAKE AN OFFERING OF ANY AMERICAN DEPOSITARY RECEIPTS REPRESENTING ITS SHARES, AND THE SHARES OFFERED WILL BE SUBJECT TO CERTAIN RESTRICTIONS ON DEPOSIT IN THE AMERICAN DEPOSITARY RECEIPT FACILITY OF THE COMPANY.

The completion of the allocation procedure of the Offering is expected to occur on November 11, 2025. Shares purchased in the Offering are expected to begin trading on the São Paulo Stock Exchange (B3 S.A. – Brasil, Bolsa, Balcão) on the second business day after the disclosure of the completion of the allocation procedure, and the settlement of the Offering is expected to occur on the third business day after the completion of the allocation procedure.

The Offering of the Shares has not been and will not be registered under the Securities Act, or any other U.S. federal and state securities laws, and the Shares (including any additional Shares, if applicable) may not be offered, sold, pledged or otherwise transferred in the United States or to, or for the account or benefit of, U.S. persons (as defined in Regulation S under the Securities Act), unless pursuant to a registration statement or in transactions exempt from, or not subject to, the registration requirements of the Securities Act.

Any information contained herein shall not be taken, transmitted, disclosed, distributed, or disseminated in the United States of America. The distribution of announcements and the offering and sale of securities in certain jurisdictions may be prohibited by law.

This material fact is disclosed for informative purpose only and shall not, under any circumstances, be interpreted as, nor constitute, an investment recommendation, or offer to sell, advertise, solicit, or offer to buy or an announcement of a public offering of or an invitation to purchase or subscribe for any securities issued by the Company (including the Shares and additional Shares, if applicable), and shall not constitute an offer, solicitation or sale in any jurisdiction in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of that jurisdiction.

The Company will maintain its shareholders and the market informed of any relevant updates regarding the Offering through the communication channels the Company regularly uses for the disclosure of relevant information.