[6-K] Cosan S.A. Current Report (Foreign Issuer)

Rhea-AI Filing Summary

Cosan S.A. announced executive and board changes. Rodrigo Araujo Alves resigned as Chief Financial and Investor Relations Officer, and Rafael Bergman will assume the role effective December 05, 2025. For the Board of Directors, effective November 19, 2025, Pedro Isamu Mizutani, Luis Henrique Cals de Beauclair Guimarães, Silvia Brasil Coutinho, and Vasco Augusto Pinto da Fonseca Dias Júnior resigned. André Santos Esteves was elected Vice Chairman, and Renato Antônio Secondo Mazzola and Ralph Gustavo Rosenberg were elected as Board Members.

Cosan also noted corresponding governance changes at subsidiaries Rumo, Compass, and jointly controlled Raízen, with Moove reflecting Rodrigo Araujo’s resignation and the appointments of Mazzola and Rosenberg. Management will address these updates during the earnings conference call on November 17, 2025.

Insights

Corporate governance analyst

Leadership reshuffle across Cosan and key affiliates; neutral impact.

The filing lists executive turnover and board refreshes at Cosan with effective dates for the CFO transition and multiple director changes. It also aligns governance updates at major subsidiaries Rumo, Compass, and Raízen, plus Moove. These are structural updates without disclosed financial terms.

Board continuity is maintained via new appointments, including André Santos Esteves as Vice Chairman and two new directors. The business effect depends on subsequent strategic decisions; the text provides no operational changes or targets.

Near term, watch for management commentary during the earnings call on November 17, 2025 for any strategic priorities tied to the new leadership. No cash-flow or performance metrics are included here.

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16
OR 15d-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934

For the month of November 2025

Commission File Number: 001-40155

Cosan S.A.

(Exact name of registrant as specified in its charter)

N/A

(Translation of registrant’s name into English)

Av. Brigadeiro Faria Lima, 4100, – 16th floor
São Paulo, SP 04538-132 Brazil
(Address of principal executive offices)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F:

Form 20-F X Form 40-F

COSAN S.A.

Corporate Taxpayer ID (CNPJ): 50.746.577/0001-15

Company Registry (NIRE): 35.300.177.045

Publicly Held Company

CVM 19836

MATERIAL FACT

COSAN S.A. (B3: CSAN3; NYSE: CSAN) (“Cosan” or “Company”) in compliance with the provisions of CVM Resolution No. 44 of August 23, 2021, informs its shareholders and the market in general that the Board of Directors, in meeting held on this date, approved changes to the composition of its Executive Board and Board of Directors.

Rodrigo Araujo Alves, current Chief Financial and Investor Relations Officer of the Company, resigned from his position. Rafael Bergman will assume the role of Chief Financial and Investor Relations Officer of the Company. These changes will become effective as of December 05, 2025.

Regarding the Board of Directors, the changes listed below will become effective on November 19, 2025.

• Mr. Pedro Isamu Mizutani, Mr. Luis Henrique Cals de Beauclair Guimarães, Ms. Silvia Brasil Coutinho, and Mr. Vasco Augusto Pinto da Fonseca Dias Júnior have resigned from their positions as Board Members;
• Mr. André Santos Esteves has been elected Vice Chairman of the Board of Directors; and
• Mr. Renato Antônio Secondo Mazzola and Mr. Ralph Gustavo Rosenberg have been elected as Board Members.

Additionally, the Company informs that, on this date, changes are also being communicated in the respective Boards of Directors of its subsidiaries Rumo, Compass, and its jointly controlled entity Raízen. At Moove, the resignation of Rodrigo Araujo and the appointment of Mr. Renato Antônio Secondo Mazzola and Mr. Ralph Gustavo Rosenberg will also take place.

All information is available in the Material Facts disclosed today by the respective companies. The Company’s executive officers will be available for further clarification during the earnings conference call to be held on November 17, 2025, in accordance with the corporate calendar.

São Paulo, November 14, 2025.

Rodrigo Araujo

Chief Financial and Investor Relations Officer

SIGNATURES

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, thereunto duly authorized. 

Date: November 14, 2025

	COSAN S.A.
	By:	/s/ Rodrigo Araujo Alves
		Name:            Rodrigo Araujo Alves
		Title: Chief Financial Officer

FAQ

What leadership changes did CSAN announce in this 6-K?

Rodrigo Araujo Alves resigned as CFO and IRO; Rafael Bergman will assume the role effective December 05, 2025.

What changes occurred on Cosan’s Board of Directors (CSAN)?

Effective November 19, 2025, four directors resigned; André Santos Esteves became Vice Chairman; Renato Mazzola and Ralph Rosenberg joined the board.

Are Cosan’s subsidiaries affected by these governance changes?

Yes. Changes were also communicated at Rumo, Compass, and jointly controlled Raízen; Moove reflects the CFO resignation and two new appointments.

When will Cosan discuss these updates with investors (CSAN)?

Management will provide clarifications during the earnings conference call on November 17, 2025.

Do these changes include financial terms or guidance for CSAN?

No financial metrics or guidance are included; the notice focuses on executive and board composition changes.

Who is the new Vice Chairman of Cosan’s Board (CSAN)?

André Santos Esteves was elected Vice Chairman effective November 19, 2025.