github-repositories

What changed

Lasso Security reported that Microsoft Copilot could return content from GitHub repositories that had been public briefly but later set to private or deleted. Lasso attributed this to Bing's caching system, which stored "zombie data" from over 20,000 repositories. The cached content allegedly included sensitive information such as access keys, tokens, and internal packages. Microsoft reportedly classified the issue as low severity and applied only partial mitigations.

Timeline

1. 15 Aug 2025Microsoft Copilot Reportedly Able to Access Cached Data from Since-Private GitHub Repositories
   Incident82%

   • Thousands of exposed GitHub repositories, now private, can still be accessed through Copilothttps://techcrunch.com/2025/02/26/thousands-of-exposed-github-repositories-now-private-can-still-be-accessed-through-copilot/
   • Wayback Copilot: Using Microsoft's Copilot to Expose Thousands of Private GitHub Repositorieshttps://www.lasso.security/blog/lasso-major-vulnerability-in-microsoft-copilot
   • AI Incident Database - Incident 1174https://incidentdatabase.ai/cite/1174/

   Thousands of exposed GitHub repositories, now private, can still be accessed through CopilotWayback Copilot: Using Microsoft's Copilot to Expose Thousands of Private GitHub RepositoriesAI Incident Database - Incident 1174

PSF mapping