UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

FORM 6-K

Report of Foreign Issuer

Pursuant To Rule 13a-16 Or 15d-16 of the

Securities Exchange Act of 1934

For the month of November 2025

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. 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 ☐

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(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 Rule 101(b)(7):

Yes ☐ No ☒

Table of Contents

CONTENTS

Independent auditor's report on the Condensed interim individual and consolidated financial statements	3
Interim statement of financial position	5
Interim statement of profit or loss	7
Interim statement of comprehensive income	8
Interim statement of changes in equity	9
Interim statement of cash flows	11
Interim statement of value-added	14
1. Operational context	15
2. Relevant events of the period	16
2.1 Investments	16
2.2 New debts	19
3. Statement of compliance and material accounting policies	19
4. Segment information	21
4.1 Net sales to external customers by product/customer type	28
4.2 Information on geographical area	29
5. Financial assets and liabilities	30
5.1 Cash and cash equivalents	31
5.2 Loans, borrowings and debentures	31
5.3 Derivative financial instruments	34
5.4 Related parties	40
5.5 Trade payables	43
5.6 Fair value measurements	43
5.7 Financial risk management	44
6. Investment in subsidiaries and associates	48
6.1 Investments in subsidiaries	48
6.2 Non-controlling interest in subsidiaries	51
6.3 Acquisition of subsidiaries	53
7. Investment in joint ventures	55
8. Property, plant and equipment, intangible assets and goodwill, right-of-use assets and impairment loss	56
8.1 Property, plant and equipment	56
8.2 Intangible assets and goodwill	57
8.3 Right-of-use assets	58
8.4 Impairment loss	59
9. Income taxes	59
10. Provision for legal proceedings and judicial deposits	63
11. Shareholders' equity	66
12. Earnings per share	68
13. Net sales	69
14. Costs and expenses by nature	70
15. Other operation income (expenses), net	71
16. Financial results, net	72
17. Share-based payment	73
18. Subsequent events	73

Table of Contents

Graphics

Report on review of parent company

and consolidated condensed interim
financial statements

To the Board of Directors and Stockholders

Cosan S.A.

Introduction

We have reviewed the accompanying interim statement of financial position of Cosan S.A. ("Company") as at September 30, 2025 and the related statements of profit or loss and other comprehensive income for the quarter and nine-month period then ended, and the statements of changes in equity and cash flows for the nine-month period then ended, as well as the accompanying consolidated interim statement of financial position of the Company and its subsidiaries ("Consolidated") as at September 30, 2025 and the related consolidated statements of profit or loss and other comprehensive income for the quarter and nine-month period then ended, and the consolidated statements of changes in equity and cash flows for the nine-month period then ended, and explanatory notes.

Management is responsible for the preparation and presentation of these parent company and consolidated condensed interim financial statements in accordance with the accounting standard CPC 21, Interim Financial Reporting, of the Brazilian Accounting Pronouncements Committee (CPC), and International Accounting Standard (IAS) 34 - Interim Financial Reporting, of the International Accounting Standards Board (IASB). Our responsibility is to express a conclusion on these condensed interim financial statements based on our review.

Scope of review

We conducted our review in accordance with Brazilian and International Standards on Reviews of Interim Financial Information (NBC TR 2410 - Review of Interim Financial Information Performed by the Independent Auditor of the Entity, and ISRE 2410 - Review of Interim Financial Information Performed by the Independent Auditor of the Entity, respectively). A review of interim financial information consists of making inquiries, primarily of persons responsible for financial and accounting matters, and applying analytical and other review procedures. A review is substantially less in scope than an audit conducted in accordance with Brazilian and International Standards on Auditing and consequently did not enable us to obtain assurance that we would become aware of all significant matters that might be identified in an audit. Accordingly, we do not express an audit opinion.

Conclusion

Based on our review, nothing has come to our attention that causes us to believe that the accompanying parent company and consolidated condensed interim financial statements referred to above are not prepared, in all material respects, in accordance with CPC 21 and IAS 34.

Table of Contents

Graphics

Statements of value added

The interim condensed financial statements referred to above include the parent company and consolidated statements of value added for the nine-month period ended September 30, 2025. These statements are the responsibility of the Company's management and are presented as supplementary information under IAS 34. These statements have been subjected to review procedures performed together with the review of the condensed interim financial statements for the purpose of concluding whether they are reconciled with the condensed interim financial statements and accounting records, as applicable, and if their form and content are in accordance with the criteria defined in the accounting standard CPC 09 - "Statement of Value Added". Based on our review, nothing has come to our attention that causes us to believe that these statements of value added have not been properly prepared, in all material respects, in accordance with the criteria established in this accounting standard, and consistent with the parent company and consolidated condensed interim financial statements taken as a whole.

Audit and review of previous year's figures

The condensed interim financial statements referred to in the first paragraph include accounting information corresponding to the statements of profit or loss and other comprehensive income for the for the quarter and nine-month period ended September 30, 2024, and the statements of changes in equity, cash flows and value added for the nine-month period ended September 30, 2024, obtained from the condensed interim financial statements for that period, and the statement of financial position as of December 31, 2024, obtained from the financial statements ended December 31, 2024, presented for comparison purposes. The review of the condensed interim financial statements for the period ended September 30, 2024 and the audit of the financial statements for the year ended December 31, 2024 were conducted under the responsibility of other independent auditors, who issued review and audit reports dated November 13, 2024, and March 10, 2025, respectively, without qualifications.

São Paulo, November 14, 2025

PricewaterhouseCoopers

Auditores Independentes Ltda.

CRC 2SP000160/O-5

Alessandro Marchesino de Oliveira

Contador CRC 1SP265450/O-8

Table of Contents

Interim statement of financial position

(In thousands of Brazilian reais - R$)

		Parent Company		Consolidated
	Note	September 30, 2025	December 31, 2024	September 30, 2025	December 31, 2024
Assets
Cash and cash equivalents	5.1	2,693,617	2,201,267	12,898,403	16,903,542
Restricted cash		—	—	11,951	28,006
Marketable securities		147,105	805,335	3,203,347	3,272,941
Trade receivables		—	—	3,844,066	3,730,364
Derivative financial instruments	5.3	—	18,402	84,178	905,341
Inventories		—	—	2,112,281	2,072,905
Receivables from related parties	5.4	134,559	114,099	189,499	197,063
Income tax receivable		662,466	453,308	1,039,160	793,721
Other current tax receivable		5,279	5,364	905,912	886,136
Dividend receivable		11,850	19,377	24,617	153,548
Reduction of capital receivable		6,494	1,013,714	—	—
Sectorial financial assets		—	—	262,761	221,947
Other financial assets		—	—	417	675
Other current assets		56,400	50,896	1,084,133	629,426
Current assets		3,717,770	4,681,762	25,660,725	29,795,615
Current assets held for sale		796,949	796,211	1,224,866	978,788
		4,514,719	5,477,973	26,885,591	30,774,403

Trade receivables		—	—	170,878	265,370
Marketable securities		245,793	—	335,608	113,360
Restricted cash		191	—	205,574	146,297
Deferred tax assets	9	1,231,453	1,758,410	3,621,453	4,495,296
Receivables from related parties	5.4	96,699	292,882	22,730	202,826
Income tax receivable		—	—	104,508	264,308
Other non-current tax receivable		34,750	35,177	1,680,597	1,334,553
Judicial deposits	10	347,356	416,969	1,035,371	1,056,690
Derivative financial instruments	5.3	42,199	1,547,093	1,655,014	2,893,987
Sectorial financial assets		—	—	436,053	509,695
Other non-current assets		115,174	140,594	931,694	739,386
Other financial assets		—	—	4,685	3,820
Investment in subsidiaries and associates	6.1	22,109,711	31,308,696	1,717,705	10,678,566
Investment in joint ventures	7	893,934	1,193,072	7,900,524	10,545,044
Property, plant and equipment	8.1	36,308	39,038	25,299,016	23,019,016
Intangible assets and goodwill	8.2	11,505	9,873	26,475,778	26,330,785
Contract assets		—	—	1,039,919	1,114,830
Right-of-use assets	8.3	14,376	17,557	9,726,999	9,958,751
Investment property		—	—	16,489,000	16,818,919
Non-current assets		25,179,449	36,759,361	98,853,106	110,491,499

Total assets		29,694,168	42,237,334	125,738,697	141,265,902

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

Table of Contents

Interim statement of financial position

(In thousands of Brazilian reais - R$)

		Parent Company		Consolidated
	Note	September 30, 2025	December 31, 2024	September 30, 2025	December 31, 2024
Liabilities
Loans, borrowings and debentures	5.2	386,529	347,032	3,890,069	4,403,148
Leases		9,935	9,227	994,418	1,007,533
Derivative financial instruments	5.3	378,723	1,074,991	2,150,537	2,504,117
Trade payables	5.5	7,986	2,900	4,071,632	5,168,593
Employee benefits payables		38,134	43,356	693,530	794,906
Income tax payables		16,020	18,514	327,950	414,823
Other taxes payable		28,981	78,197	559,104	637,842
Dividends payable	11	39	3,495	95,699	96,722
Reduction of capital payable		—	—	—	486,285
Concessions payable		—	—	186,155	166,273
Related party payables	5.4	157,520	210,620	342,008	416,410
Sectorial financial liabilities		—	—	80,054	64,718
Other financial liabilities	5	—	—	629,202	770,103
Other current liabilities		320,788	298,534	867,270	895,223
Current liabilities		1,344,655	2,086,866	14,887,628	17,826,696
Liabilities related to assets held for sale		—	—	86,145	86,138
	`	1,344,655	2,086,866	14,973,773	17,912,834

Loans, borrowings and debentures	5.2	15,686,375	21,003,523	57,023,731	62,052,278
Leases		10,324	15,232	5,362,893	5,502,220
Derivative financial instruments	5.3	315,924	29,883	858,913	966,087
Trade payables	5.5	—	—	19,955	19,256
Employee benefits payables		—	—	17,008	19,101
Other taxes payable		146,122	216,203	173,887	255,245
Income tax payables		6,539	—	78,816	—
Provision for legal proceedings	10	310,936	308,607	2,093,467	2,044,633
Concessions payable		—	—	3,663,704	3,554,917
Investments with unsecured liabilities	6.1	350,582	263,722	—	—
Related party payables	5.4	5,260,428	7,052,404	1,175	1,078
Post-employment benefits		373	279	573,846	526,620
Deferred tax liabilities	9	—	—	5,999,171	5,973,506
Sectorial financial liabilities		—	—	2,114,799	1,975,521
Deferred income		—	—	14,845	16,589
Other financial liabilities	5	—	—	—	297,736
Other non-current liabilities		360,587	356,851	714,723	749,919
Non-current liabilities		22,448,190	29,246,704	78,710,933	83,954,706
Total liabilities		23,792,845	31,333,570	93,684,706	101,867,540

Shareholders’ equity	11
Share capital		8,182,739	8,832,544	8,182,739	8,832,544
Treasury shares		(78,354)	(50,708)	(78,354)	(50,708)
Additional paid-in capital		1,161,285	2,205,878	1,161,285	2,205,878
Accumulated other comprehensive income		554,767	565,855	554,767	565,855
Profit reserve		—	8,773,990	—	8,773,990
Retained losses		(3,919,114)	(9,423,795)	(3,919,114)	(9,423,795)
Company		5,901,323	10,903,764	5,901,323	10,903,764
Non-controlling interests	6.2	—	—	26,152,668	28,494,598
Total shareholders' equity		5,901,323	10,903,764	32,053,991	39,398,362
Total liabilities and shareholders' equity		29,694,168	42,237,334	125,738,697	141,265,902

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

Table of Contents

Interim statement of profit or loss
(In thousands of Brazilian reais - R$, except earnings (loss) per share)

		Parent Company				Consolidated
		Period of three months ended September 30,		Period of nine months ended September 30,		Period of three months ended September 30,		Period of nine months ended September 30,
	Note	2025	2024	2025	2024	2025	2024	2025	2024
Net sales	13	—	—	—	—	10,664,185	11,646,297	30,804,438	32,182,361
Cost of sales	14	—	—	—	—	(6,936,477)	(7,809,169)	(20,609,888)	(21,875,210)
Gross profit		—	—	—	—	3,727,708	3,837,128	10,194,550	10,307,151

Selling expenses	14	—	—	—	—	(512,904)	(417,549)	(1,410,489)	(1,155,450)
General and administrative expenses	14	(63,622)	(114,068)	(199,173)	(329,269)	(626,925)	(949,192)	(1,805,581)	(2,143,860)
Other operating income (expenses), net	15	(7,053)	(20,191)	158,948	(5,796)	407,544	53,911	1,420,468	220,445
Impairment	15	—	—	—	—	(316,955)	(109,063)	(1,000,094)	(2,683,879)
Operating (expenses) income		(70,675)	(134,259)	(40,225)	(335,065)	(1,049,240)	(1,421,893)	(2,795,696)	(5,762,744)

Loss (profit) before equity in earnings of investees, finance results and income taxes		(70,675)	(134,259)	(40,225)	(335,065)	2,678,468	2,415,235	7,398,854	4,544,407

Interest in earnings (losses) of subsidiaries and associates	6.1	(224,015)	693,836	(671,243)	2,271,826	64,580	612,280	163,233	1,907,075
Interest in (losses) earnings of joint ventures	7	(116,455)	(13,069)	(337,528)	(8,017)	(1,030,037)	(105,337)	(2,997,532)	(58,271)
Equity in earnings (losses) of investees		(340,470)	680,767	(1,008,771)	2,263,809	(965,457)	506,943	(2,834,299)	1,848,804

Finance expense		(693,241)	(581,346)	(2,080,692)	(1,736,655)	(2,107,607)	(1,825,539)	(6,882,193)	(5,820,846)
Finance income		142,128	91,516	478,158	191,887	823,761	680,596	2,578,368	2,022,082
Foreign exchange, net		206,266	303,676	1,706,669	(1,548,901)	357,808	463,788	2,946,263	(2,510,248)
Net effect of derivatives		(501,732)	(249,751)	(2,227,807)	(110,802)	(1,254,119)	(736,139)	(4,528,479)	590,586
Finance results net	16	(846,579)	(435,905)	(2,123,672)	(3,204,471)	(2,180,157)	(1,417,294)	(5,886,041)	(5,718,426)

Profit (loss) before income taxes		(1,257,724)	110,603	(3,172,668)	(1,275,727)	(467,146)	1,504,884	(1,321,486)	674,785

Income taxes	9
Current		(272)	(3,677)	(272)	(7,526)	(449,452)	(540,995)	(1,124,173)	(1,368,911)
Deferred		72,816	164,373	(746,174)	1,135,269	82,169	30,950	(892,267)	983,024
		72,544	160,696	(746,446)	1,127,743	(367,283)	(510,045)	(2,016,440)	(385,887)
		(1,185,180)	271,299	(3,919,114)	(147,984)	(834,429)	994,839	(3,337,926)	288,898

Results of the operations discontinued, net of taxes		—	21,582	—	21,582	—	31,935	—	31,935

Profit (loss) for the period net		(1,185,180)	292,881	(3,919,114)	(126,402)	(834,429)	1,026,774	(3,337,926)	320,833

Profit (loss) attributable to:
Owners of the Company		(1,185,180)	292,881	(3,919,114)	(126,402)	(1,185,180)	292,881	(3,919,114)	(126,402)
Non-controlling interests		—	—	—	—	350,751	733,893	581,188	447,235
		(1,185,180)	292,881	(3,919,114)	(126,402)	(834,429)	1,026,774	(3,337,926)	320,833

Earnings (loss) per share	12
Basic						R$(0.64)	R$0.15	R$(2.11)	R$(0.08)
Diluted						R$(0.64)	R$0.15	R$(2.11)	R$(0.08)

Earnings per share - discontinued operations	12
Basic						R$—	R$0.01	R$—	R$0.01
Diluted						R$—	R$0.01	R$—	R$0.01

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

Table of Contents

Interim statement of other comprehensive income
(In thousands of Brazilian reais - R$, except earnings (loss) per share)

	Parent Company				Consolidated
	Period of three months ended September 30,		Period of nine months ended September 30,		Period of three months ended September 30,		Period of nine months ended September 30,
	2025	2024	2025	2024	2025	2024	2025	2024
Profit (loss) for the period	(1,185,180)	292,881	(3,919,114)	(126,402)	(834,429)	1,026,774	(3,337,926)	320,833

Other comprehensive income:
Items that are or may be reclassified subsequently to profit or loss ⁽ⁱ⁾:
Foreign currency translation differences	(77,053)	(283,130)	(146,258)	(118,926)	(95,311)	(358,679)	(140,900)	(164,175)
Gain (loss) on cash flow hedge	47,216	29,962	219,913	(129,794)	58,766	60,077	278,126	(231,682)
Deferred taxes	—	—	—	—	(7,785)	(18,868)	(55,358)	63,181
	(29,837)	(253,168)	73,655	(248,720)	(44,330)	(317,470)	81,868	(332,676)

Items that will not be reclassified to profit or loss:
Actuarial gains (losses) with defined benefit plan	(12)	(4,582)	(22,496)	12,386	(89,107)	9,552	(126,726)	19,700
Loss (gain) in fair value of financial liabilities designated at fair value through profit or loss attributable to changes in credit risk ⁽ⁱ⁾	(70,745)	—	(70,745)	—	(82,979)	—	(82,979)	—
Deferred taxes	—	—	8,498	(1,668)	67,568	(14,174)	91,592	(7,450)
	(70,757)	(4,582)	(84,743)	10,718	(104,518)	(4,622)	(118,113)	12,250

Comprehensive income of operations continued	(1,285,774)	13,549	(3,930,202)	(385,986)	(983,277)	672,747	(3,374,171)	(31,528)
Comprehensive income from discontinued operations	—	21,582	—	21,582	—	31,935	—	31,935
Total comprehensive income (loss) for the period	(1,285,774)	35,131	(3,930,202)	(364,404)	(983,277)	704,682	(3,374,171)	407

Comprehensive income (loss) attributable to:
Owners of the Company	(1,285,774)	35,131	(3,930,202)	(364,404)	(1,285,774)	35,131	(3,930,202)	(364,404)
Non-controlling interests	—	—	—	—	302,497	669,551	556,031	364,811
	(1,285,774)	35,131	(3,930,202)	(364,404)	(983,277)	704,682	(3,374,171)	407

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

(i) For the Parent Company, the effects arise from the equity method of accounting for its subsidiaries.

Table of Contents

Interim statement of changes in equity

(In thousands of Brazilian reais - R$)

			Capital reserve			Profit reserve			Shareholders’ equity attributable to
	Share capital	Treasury shares	Corporate transactions - Law 6.404/76	Additional paid-in capital	Accumulated other comprehensive income	Legal	Statutory reserve	Accumulated losses	Controlling shareholders	Non-controlling shareholders	Total shareholders' equity
Balance as at January 1, 2025	8,832,544	(50,708)	737	2,205,141	565,855	58,802	8,715,188	(9,423,795)	10,903,764	28,494,598	39,398,362

Profit (loss) for the period	—	—	—	—	—	—	—	(3,919,114)	(3,919,114)	581,188	(3,337,926)

Other comprehensive income
Gain from cash flow hedge	—	—	—	—	219,913	—	—	—	219,913	2,855	222,768
Foreign currency translation differences	—	—	—	—	(146,258)	—	—	—	(146,258)	5,358	(140,900)
Actuarial gains (losses) on defined benefit plans, net of tax	—	—	—	—	(13,998)	—	—	—	(13,998)	(21,136)	(35,134)
Loss in fair value of financial liabilities designated at fair value through profit or loss attributable to changes in credit risk					(70,745)				(70,745)	(12,234)	(82,979)
Total comprehensive income (loss) for the period	—	—	—	—	(11,088)	—	—	(3,919,114)	(3,930,202)	556,031	(3,374,171)

Transactions with owners of the Company contributions and distributions:
Effect arising from capital increase in subsidiary	—	—	—	(83,393)	—	—	—	—	(83,393)	83,393	—
Own shares acquired (note 11 (a))	—	(34,022)	—	—	—	—	—	—	(34,022)	—	(34,022)
Share-based payments	—	6,376		1,114	—	—	—	—	7,490	9,380	16,870
Absorption of accumulated losses (note 11 (c))	(649,805)	—	—	—	—	(58,802)	(8,715,188)	9,423,795	—	—	—
Dividends	—	—	—	—	—	—	—	—	—	(1,805,462)	(1,805,462)
Employee share schemes - value of employee services	—	—	—	26,595	—	—	—	—	26,595	2,932	29,527
Total contributions and distributions	(649,805)	(27,646)	—	(55,684)	—	(58,802)	(8,715,188)	9,423,795	(83,330)	(1,709,757)	(1,793,087)

Transactions with owners of the Company:
Change of shareholding interest in subsidiary (note 6.1)	—	—	—	(988,909)	—	—	—	—	(988,909)	(1,188,204)	(2,177,113)
Total transactions with owners of the Company	—	—	—	(988,909)	—	—	—	—	(988,909)	(1,188,204)	(2,177,113)

Total transactions with owners of the Company contributions and distributions	(649,805)	(27,646)	—	(1,044,593)	—	(58,802)	(8,715,188)	9,423,795	(1,072,239)	(2,897,961)	(3,970,200)

Balance as at September 30, 2025	8,182,739	(78,354)	737	1,160,548	554,767	—	—	(3,919,114)	5,901,323	26,152,668	32,053,991

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

Table of Contents

Interim statement of changes in equity

(In thousands of Brazilian reais - R$)

			Capital reserve			Profit reserve				Shareholders’ equity attributable to
	Share capital	Treasury shares	Corporate transactions - Law 6.404/76	Additional paid-in capital	Accumulated other comprehensive income	Legal	Statutory reserve	Profit retention	Accumulated losses	Controlling shareholders	Non-controlling shareholders	Total shareholders' equity
Balance as at January 1, 2024	8,682,544	(93,917)	737	2,561,227	314,325	58,802	8,610,796	820,793	—	20,955,307	30,025,873	50,981,180
Loss (profit) for the period	—	—	—	—	—	—	—	—	(126,402)	(126,402)	447,235	320,833
Other comprehensive income
Loss from cash flow hedge	—	—	—	—	(129,794)	—	—	—	—	(129,794)	(38,707)	(168,501)
Foreign currency translation differences	—	—	—	—	(118,926)	—	—	—	—	(118,926)	(45,249)	(164,175)
Actuarial gains with defined benefit plan, net of tax	—	—	—	—	10,718	—	—	—	—	10,718	1,532	12,250
Total comprehensive income (loss) for the period	—	—	—	—	(238,002)	—	—	—	(126,402)	(364,404)	364,811	407
Transactions with owners of the Company contributions and distributions:
Capital increase	150,000	—	—	—	—	—	(150,000)	—	—	—	—	—
Capital reduction in subsidiary	—	—	—	—	—	—	—	—	—	—	(20,629)	(20,629)
Share-based payment	—	114,516	—	(202,320)	—	—	—	—	—	(87,804)	8,020	(79,784)
Loss in dividend distribution to non-controlling shareholders	—	—	—	(712)	—	—	—	—	—	(712)	928	216
Dividends	—	—	—	—	—	—	(566,401)	—	—	(566,401)	(1,708,707)	(2,275,108)
Own shares acquired	—	(162,174)	—	—	—	—	—	—	—	(162,174)	—	(162,174)
Cancellation of treasury shares	—	118,975	—	(118,975)	—	—	—	—	—	—	—	—
Business combination	—	—	—	—	—	—	—	—	—	—	574,598	574,598
Employee share schemes - value of employee services	—	—	—	153,659	—	—	—	—	—	153,659	64,763	218,422
Total contributions and distributions	150,000	71,317	—	(168,348)	—	—	(716,401)	—	—	(663,432)	(1,081,027)	(1,744,459)

Transactions with owners of the Company:
Change of shareholding interest in subsidiary	—	—	—	(3,652)	—	—	—	—	—	(3,652)	2,972	(680)
Total transactions with owners of the Company	—	—	—	(3,652)	—	—	—	—	—	(3,652)	2,972	(680)
Total transactions with owners of the Company contributions and distributions	150,000	71,317	—	(172,000)	—	—	(716,401)	—	—	(667,084)	(1,078,055)	(1,745,139)

Balance as at September 30, 2024	8,832,544	(22,600)	737	2,389,227	76,323	58,802	7,894,395	820,793	(126,402)	19,923,819	29,312,629	49,236,448

The accompanying notes are an integral part of the condensed interim individual and consolidated financial statements.

Table of Contents

Interim statement of cash flows

(In thousands of Brazilian reais - R$)

		Parent Company		Consolidated
		Period of nine months ended September 30,
	Note	2025	2024	2025	2024
Cash flows from operating activities
Profit (loss) before income taxes		(3,172,668)	(1,275,727)	(1,321,486)	674,785
Adjustments for:
Depreciation and amortization	14	14,929	11,731	2,961,091	2,900,785
Impairment	15	—	—	1,000,094	2,683,879
Interest in earnings (losses) of subsidiaries and associates	6.1	671,243	(2,271,826)	(163,233)	(1,907,075)
Interest in earnings (losses) of joint ventures	7	337,528	8,017	2,997,532	58,271
Loss (gain) on disposed assets	15	—	7	68,732	(24,091)
Share-based payment	17	18,964	33,679	51,006	255,309
Provision for legal proceedings	15	58,101	21,464	169,085	202,705
Interest, derivatives, monetary and foreign exchange, net		2,457,137	3,257,700	7,300,273	6,822,918
Sectorial financial assets and liabilities, net		—	—	110,289	(55,329)
Provisions for employee benefits		32,969	27,737	320,762	286,153
Allowance for expected credit losses		—	—	66,823	35,647
Profit on sale of investment	15	—	—	—	383,205
Insurance claims		—	—	(706,541)	—
Income from finance investments		(9,143)	—	(9,143)	(63,966)
Previously recognized gain in other comprehensive income reclassified to profit or loss upon disposal of investment	15	(206,388)	—	(206,388)	—
Other		370	649	102,217	(230,280)
		203,042	(186,569)	12,741,113	12,022,916
Variation in:
Trade receivable		—	—	47,193	(313,803)
Inventories		—	—	(236,036)	(119,183)
Other taxes, net		(7,313)	(30,234)	(426,500)	(193,710)
Income tax		(6,061)	118,808	(507,716)	(154,873)
Income taxes paid		—	—	(475,545)	(922,299)
Related parties, net		(6,765)	7,485	(78,567)	61,431
Trade payables		5,222	3,000	(107,277)	(79,927)
Employee benefits		(42,904)	(55,812)	(433,741)	(459,022)
Provision for legal proceedings		3,778	2,666	(158,968)	(257,964)
Derivative financial instruments		—	—	(52,311)	(13,717)
Other financial liabilities		—	—	(170,075)	183,486
Judicial deposits		(8,334)	(2,459)	(35,651)	(139,637)
Post-employment benefit obligation		—	—	(30,990)	(27,091)
Other assets and liabilities, net		30,625	4,389	(405,399)	(210,288)
		(31,752)	47,843	(3,071,583)	(2,646,597)

Net cash generated from (used in) operating activities		171,290	(138,726)	9,669,530	9,376,319

Cash flows from investing activities
Capital contribution to associates		(334,142)	(4,173,198)	(15,000)	—
Capital contribution in joint ventures		—	(12,337)	—	(12,337)
Cost of acquiring new business, net of cash acquired		—	—	(326,885)	(330,593)

Sale (purchase) of marketable securities, net		689,272	(180,700)	249,742	(948,373)
Restricted cash		(191)	43,048	(45,963)	42,266
Dividends received from subsidiaries and associates		618,978	2,639,937	73,864	973,977

Table of Contents

Interim statement of cash flows

(In thousands of Brazilian reais - R$)

		Parent Company		Consolidated
		Period of nine months ended September 30,
	Note	2025	2024	2025	2024
Dividends received from joint venture		5,184	228,342	45,640	293,912
Dividends received from finance investment		87,608	—	87,608	—
Other financial assets		(148)	—	76	(406)
Cash in the incorporation operation		10,089	352	—	—
Capital reduction in subsidiaries		1,022,748	735,227	26,000	—
Acquisition of property, plant and equipment, intangible and contract assets		(8,775)	(7,572)	(6,303,395)	(5,185,588)
Proceeds from the sale of investments		8,911,587	16,847	8,911,587	2,096,475
Related parties		25,592	—	25,592	—
Operation discontinued		—	—	7,425	2,886
Acquisition of subsidiary		—	—	(250,937)	(17,047)
Receipt of derivative financial instruments, except debt		1,021	—	1,021	103,147
Payment of derivative financial instruments, except debt		(1,006,973)

Cosan S.A. 6-K