Form 6-K Vista Energy, S.A.B. de For: Jul 15

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

UNDER SECURITIES EXCHANGE ACT OF 1934

For the month of July 2026

Commission File No. 001-39000

Vista Energy, S.A.B. de C.V.

(Exact Name of the Registrant as Specified in the Charter)

N.A.

(Translation of Registrant’s Name into English)

Torre Mapfre,

243 Paseo de la Reforma Avenue, 18th Floor

Cuauhtémoc, Alcaldía Cuauhtémoc

06500, Mexico City

Mexico

(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 ☐

Sustainability-Related Financial Disclosures Report

Mexico City, July 15, 2026 — Vista Energy, S.A.B. de C.V. (“Vista” or the “Company”) (NYSE: VIST; BMV: VISTA) announced today that it has filed its Sustainability-Related Financial Disclosures Report for the year ended December 31, 2025 with the Mexican Stock Exchange’s (Bolsa Mexicana de Valores, S.A.B. de C.V.) and the Mexican National Banking and Securities Commission (Comisión Nacional Bancaria y de Valores), pursuant to article 82 Bis of the Mexican Securities Act (Ley del Mercado de Valores).

The report is accessible on the Company’s website, at https://www.vistaenergy.com/en/investors or at the Mexican Stock Exchange’s (Bolsa Mexicana de Valores, S.A.B. de C.V.) website: www.bmv.com.mx, or the Mexican National Banking and Securities Commission (Comisión Nacional Bancaria y de Valores) website: www.gob.mx/cnbv.

Forward-Looking Statements

Any statements contained herein or in the attachments hereto regarding Vista that are not historical or current facts are forward-looking statements. These forward-looking statements convey Vista’s current expectations or forecasts of future events. Forward-looking statements regarding Vista involve known and unknown risks, uncertainties and other factors that may cause Vista’s actual results, performance or achievements to be materially different from any future results, performances or achievements expressed or implied by the forward-looking statements. Certain of these risks and uncertainties are described in the “Risk Factors,” “Forward-Looking Statements” and other applicable sections of Vista’s annual report filed with the United States Securities and Exchange Commission (“SEC”) on Form 20-F and other applicable filings with the SEC and Vista’s latest annual report available on the Mexican Stock Exchange’s (Bolsa Mexicana de Valores, S.A.B. de C.V.) website: www.bmv.com.mx, the Mexican National Banking and Securities Commission (Comisión Nacional Bancaria y de Valores) website: www.gob.mx/cnbv and our website: www.vistaenergy.com.

Enquiries:

Investor Relations:

[email protected]

Argentina: +54 11 3754 8500

Mexico: +52 55 8647 0128

SIGNATURE

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: July 15, 2026