The 2026 Grand Challenge on Multimedia Verification at ICMR 2026 invited participants to verify real-world multimedia content across various dimensions, such as verified evidence (source, location, time, entities, motivation) and forensic analysis. Four teams submitted complete solutions, evaluated by professional fact-checkers on a 110-point rubric across ten real-world cases. This paper presents an overview of the challenge, summarizes the participating methods, and reports the official scoreboard together with per-criterion analysis. We observe a clear trend toward multi-agent, tool-augmented LLM pipelines, but also recurring weaknesses in human oversight, reasoning grounding, and resistance to hallucination. As a result, no submission was declared a winner this year, and we outline concrete directions for the next edition.

The 2025 Grand Challenge on Multimedia Verification addresses the challenges of verifying the authenticity and context of online multimedia content. Participants analyzed real-world cases of images and videos, assessed their sources, detected any potential manipulations, and submitted detailed verification reports. The main competition was structured into three stages: Training, Validation, and Real-World Verification, which included live test cases and welcomed solutions ranging from manual methods and OSINT practices to automated tools and novel AI techniques. A total of 32 teams from 11 countries registered. The submitted solutions presented diverse pipelines that integrated forensic analysis, multimodal reasoning, and large language models (LLMs). The results demonstrate significant progress toward semi-automated verification workflows, while also exposing challenges in scalability, consistency, and reliability. In this paper, we present the challenge design, datasets, evaluation criteria, and participant outcomes, providing insights to guide future research and practice in multimedia verification.

Abstract This paper investigates the use of multimedia verification, in particular, computational tools and Open‐source Intelligence (OSINT) methods, for verifying online multimedia content in the context of the ongoing wars in Ukraine and Gaza. Our study examines the workflows and tools used by several fact‐checkers and journalists working at Faktisk, a Norwegian fact‐checking organization. Our study showcases the effectiveness of diverse resources, including AI tools, geolocation tools, internet archives, and social media monitoring platforms, in enabling journalists and fact‐checkers to efficiently process and corroborate evidence, ensuring the dissemination of accurate information. This research provides an in‐depth analysis of the role of computational tools and OSINT methods for multimedia verification. It also underscores the potentials of currently available technology, and highlights its limitations while providing guidance for future development of digital multimedia verification tools and frameworks.