Judgment of the Court (Grand Chamber) of 16 July 2026.#Criminal proceedings against M.G.D.#Reference for a preliminary ruling – Protection of the financial interests of the European Union – Article 325(1) TFEU – Convention drawn up on the basis of Article K.3 of the Treaty on European Union, on the protection of the European Communities’ financial interests – Article 2(1) – Obligation to counter fraud affecting the financial interests of the Union by taking effective deterrent measures – Obligation to provide for criminal penalties – Serious fraud affecting the financial interests of the Union – Concept – Limitation period for criminal liability – National standard of protection relating to the principle of the retroactive application of the more lenient criminal law (lex mitior principle) – Obligation for the courts of a Member State to disapply case-law of the supreme court of that Member State which is not in line with EU law – Application of the judgment of 24 July 2023, Lin (C‑107/23 PPU, EU:C:2023:606) – Constitutional prohibition on applying lex tertia – Limitation period already expired – Foreseeability of the conditions laid down by that judgment – Compatibility of that judgment with Article 7 of the Convention for the Protection of Human Rights and Fundamental Freedoms, signed in Rome on 4 November 1950.#Case C-280/25.