UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Issuer

Pursuant To Rule 13a-16Or15d-16 of the

Securities Exchange Act of 1934

For the month of May2026

Commission File Number:333-251238

COSAN S.A.

(Exact name of registrant as specified in its charter)

N/A

(Translation of registrant’s name into English)

Av.BrigadeiroFariaLima, 4100, – 16thfloor
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 Form40‑F:  

Form 20-F☒Form 40-F☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule101(b)(1):

Yes☐No☒

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule101(b)(7):

Yes☐No☒

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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: May 15, 2026

COSAN S.A.
By:	/s/ Rafael Bergman
	Name:            Rafael Bergman
	Title:Chief Financial Officer