Session report of WP.29 (World Forum for Harmonization of Vehicle Regulations), its Administrative Committee of the 1958 Agreement (AC.1), Executive Committee of the 1998 Agreement (AC.3), and Administrative Committee of the 1997 Agreement (AC.4) held 23-26 June 2026 in Geneva. AC.1 voted on 92 amendments to existing UN Regulations, one corrigendum to UN Regulation No. 79, and three new UN Regulations (Nos. 184-186) on liquid hydrogen vehicle safety, automated driving systems, and tyre abrasion performance. AC.3 established UN GTR on automated driving systems and adopted corrigendum to UN GTR No. 9 and Amendment 2 to UN GTR No. 13. WP.29 extended mandates of several informal working groups and noted accession of Mongolia and Armenia to the 1958 and 1997 Agreements respectively.