Greenhushing—the deliberate under-communication of genuine sustainability achievements —has been examined almost exclusively from an organizational standpoint, leaving the consumer side of the phenomenon largely undertheorized. This study investigates how perceived greenhushing, defined as a consumer’s perception that a brand deliberately withholds information about its environmental performance, affects young consumers’ green purchase intention. Drawing on signaling theory, trust–commitment theory and attribution theory, a model is developed in which brand trust, perceived risk and consumer green skepticism jointly mediate the relationship between perceived greenhushing and green purchase intention, while environmental concern and trait-level green skepticism are positioned as moderators. The model is estimated with partial least squares structural equation modeling (PLS-SEM) on a sample of 404 young consumers in Vietnam. Perceived greenhushing significantly erodes brand trust (β = −0.535), elevates perceived risk (β = 0.571) and activates consumer green skepticism (β = 0.477). Among the three mediators, brand trust is the dominant pathway to green purchase intention (β = 0.444), whereas the skepticism pathway is non-significant (p = 0.093). The direct effect of perceived greenhushing on green purchase intention remains negative and significant (β = −0.152), indicating partial mediation. The findings extend signaling theory to the under-studied domain of communicative absence, sharpen the conceptual boundary between greenwashing and greenhushing at the consumer level, and offer specific guidance for sustainability communication in emerging-market consumer settings.