Agent skill marketplace supply chain attack: 121 skills across 7 repos vulnerable to GitHub username hijacking, 5 scanners disagree by 10x on malicious skill rates (arXiv:2603.16572)

Key Points:

• Main threat/vulnerability/incident: A supply chain attack vulnerability has been identified in the Skills.sh and SkillsDirectory platforms, where 121 skills across 7 repositories are susceptible to GitHub username hijacking.
• Impact assessment and affected systems: This vulnerability allows malicious actors to potentially take control of legitimate agent skills by exploiting repository URLs that point to GitHub accounts, leading to unauthorized access or execution of harmful code.
• Recommended actions or mitigations: It is advised for developers and users of these platforms to implement checks on repository ownership and consider using unique identifiers that are not reliant on GitHub usernames.

Technical Details: The vulnerability arises from the reliance on GitHub repository URLs, which can be compromised if an original owner renames their account, allowing attackers to hijack the repositories.

MITRE ATT&CK Techniques: None mentioned

IOCs Mentioned: None mentioned