YPF Sociedad Anonima

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13A-16 OR 15D-16 UNDER THE SECURITIES EXCHANGE ACT OF 1934 For the month of October 2026 Commission File Number: 001-12102

YPF Sociedad Anónima (Exact name of registrant as specified in its charter)

Macacha Güemes 515 C1106BKK Buenos Aires, Argentina (Address of principal executive office)

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 ☐

YPF Sociedad Anónima TABLE OF CONTENT ITEM 1 Translation of letter to the Argentine Securities Commission dated October 8, 2026.

COMISION NACIONAL DE VALORES 25 de Mayo 175 Buenos Aires BOLSAS Y MERCADOS ARGENTINOS S.A. ("ByMA") Sarmiento 299 Buenos Aires A3 Mercados S.A. ("A3 Mercados") Maipu 1210 Buenos Aires Ref. : Relevant Information - Report on Repurchase of Notes. Ladies and Gentlemen, We are writing to you in order to comply with the CNV Rules and the corresponding regulations of ByMA and A3 Mercados We hereby inform that between October 5 and October 7, 2026, YPF S.A. (the "Company") repurchased Class XXVII Notes (YMCTO) for a total amount of Ps. 22,598,512,039.79 (twenty-two billion five hundred ninety-eight million five hundred twelve thousand thirty-nine pesos and 79/100), equivalent to a par value of US$ 14,852,887, which will be held in portfolio. The Class XXVII Notes were issued by the Company in October 2023 for a nominal value of US$ 127,904,997 under the Company's Frequent Issuer framework, with maturity in October 2026. The repurchase was made at an average price equivalent to 99.98% of their nominal value.

Margarita Chun Markets Relations Officer YPF S.A.