Summary of the 2nd International Workshop on Large Language Model Supply Chain Analysis (LLMSC 2026) co-located with FSE 2026

ACM SIGSOFT Software Engineering Notes. The 2nd International Workshop on Large Language Model Supply Chain Analysis (LLMSC 2026) was held on July 5, 2026, in Montreal, Canada, co-located with the ACM International Conference on the Foundations of Software Engineering (FSE 2026). The workshop brought together researchers and practitioners interested in understanding, engineering, and securing the increasingly complex software ecosystems surrounding large language models (LLMs). Building on LLMSC 2025 and the LLM App Store Analysis (LLMapp 2025) workshop, LLMSC 2026 provided a unified forum for studying the broader LLM software supply chain, spanning models, development frameworks, applications, agent systems, external tools, and deployment infrastructure. The workshop featured nine peer-reviewed papers covering LLM supply chain governance, multi-agent systems, vulnerabilities in LLMenabled software, agent framework engineering, Model Context Protocol (MCP) security, ecosystem evolution, pipeline attestation, and LLM-enabled software analysis. This report summarizes the evolution and organization of LLMSC 2026, its technical program, the main themes emerging from the workshop, and future plans for the LLMSC community.