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 February 2026

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

Form 40-F

Graphics

COSAN S.A.

CNPJ No. 50.746.577/0001-15

NIRE 35.300.177.045

Publicly Held Company

~~CNPJ/ME~~CVM ~~No.~~Code ~~50.746.577/0001‑15~~19836

~~NIRE~~MATERIAL ~~35.300.177.045 | CVM Code 01983‑6~~FACT

~~NOTICE~~COSAN TOS.A. ~~THE~~(B3: ~~MARKET~~CSAN3; NYSE: CSAN) (“Cosan” or “Company”), in compliance with CVM Resolution No. 44/2021, informs its shareholders and the market in general that the Company is evaluating the possibility of carrying out an initial public offering of shares issued by Compass Gás e Energia S.A. (the “Potential Offering”)

~~COSAN~~The ~~S.A.~~effective ~~(B3:~~completion ~~CSAN3;~~of ~~NYSE:~~the ~~CSAN)~~Potential ~~(“Cosan”~~Offering oris ~~“Company”)~~subject, ~~further~~among toother ~~the~~factors, ~~Notice~~ to ~~the~~domestic ~~Market~~and ~~disclosed~~international onmarket ~~January~~conditions ~~16,~~and ~~2026,~~to ~~advances~~the ~~another~~obtaining ~~step~~of inthe ~~its~~relevant ~~liability~~corporate ~~management~~approvals, ~~process~~and, as ~~provided for in the documentation~~ of ~~the~~this ~~public offerings carried out in 2025~~date, ~~focused~~there onis ~~reducing~~no ~~indebtedness~~decision ~~and~~regarding ~~financial~~the ~~costs,~~effective ~~and~~completion ~~also~~of ~~improving~~the ~~its~~Potential ~~capital structure~~Offering.

InThe ~~this~~Company ~~context,~~will ~~its~~keep ~~wholly owned subsidiary, Cosan Luxembourg S.A., is fully redeeming~~ the ~~senior~~market ~~notes~~informed ~~due~~of ~~June~~any developments ~~2030~~related ~~(“Bond~~to ~~2030”) and~~ the ~~senior~~Potential ~~notes due January 2031 (“Bond 2031”), with the principal amount of Bond 2030 totaling US$269,334,000~~Offering.~~00 and Bond 2031 totaling US$300,000,000.00.~~

~~With~~São ~~this redemption~~Paulo, ~~Cosan~~February ~~has~~23, ~~communicated total debt repayment of approximately R$6~~2026.~~2 billion to the date and will keep its shareholders and the market in general informed about the next steps of this process.~~

~~São Paulo,~~ ~~February~~Rafael ~~02, 2026~~Bergman

~~Rafael~~Chief ~~BergmanChief~~ 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: February 0223, 2026

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

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