Climate change is a pressing global issue with profound consequences for life, health, and livelihoods. Its impacts — ranging from floods and droughts to saltwater intrusion — have displaced countless individuals, intensified geopolitical conflicts, and underscored the urgent need for nations to ensure equitable and efficient management of shared resources. At the same time, efforts must focus on mitigating climate change adverse effects and safeguarding human rights, particularly for vulnerable populations.This study focuses on the Mekong River Basin (MRB), a region significantly impacted by climate change and human-induced pressures. It critically evaluates gaps in international legal frameworks designed to protect human rights within the basin and identifies key shortcomings in addressing the needs of vulnerable groups, including marginalized communities and displaced populations.ASEAN, which includes five MRB countries — Cambodia, Laos, Myanmar, Thailand, and Vietnam — is argued to play a pivotal role in facilitating dialogue on cross-border water management in the MRB. Through its regional partnership framework, ASEAN provides a platform for these countries and China, a major stakeholder in the basin, to engage in discussions aimed at achieving sustainable water resource governance. By fostering collaboration and mutual understanding, ASEAN helps to align national policies with regional objectives, promoting shared responsibility for equitable and efficient resource use.This research offers strategies and actionable solutions to strengthen regional cooperation and foster inclusive policymaking. It advocates for an integrated approach to climate adaptation that prioritizes the rights and well-being of vulnerable groups. Ultimately, the findings highlight the urgency of addressing legal and institutional gaps to ensure a sustainable and equitable future for the MRB and its inhabitants.