The complex and dynamic international landscape has elevated intellectual property (IP) to a strategic resource for national development and a focal point in international strategic competition, while innovation has become crucial for enterprises to maintain long-term competitive advantages in their global expansion. Existing literature predominantly focuses on the relationship between domestic patent litigation and corporate innovation, with limited exploration in cross-border contexts. Based on the knowledge-based view, this study selected 292 publicly listed high-tech enterprises headquartered in Asia and Europe from 2013 to 2022 as research objects and used the negative binomial regression analysis to investigate the relationship between overseas patent litigation and the innovation performance of accused enterprises. The findings revealed an inverted U-shaped relationship between the number of overseas patent litigations and the innovation performance of the accused enterprises. This inverted U-shaped relationship becomes steeper with increasing IP protection distance between home and host countries but flattens with greater diversity in the litigation experience of the accused enterprises. The study highlighted the dual effects of overseas patent litigation: a knowledge appropriability effect that restricts the accused firms′ use of proprietary knowledge and a knowledge spillover effect that inadvertently transfers valuable knowledge to the accused firms. This research has enriched the literature by supplementing research in cross-border contexts and it will provide guidance for "going global" enterprises on maximizing knowledge acquisition and innovation output when facing overseas patent attacks.