OpenAI Agents Linked to RubyGems Campaign That Gained RCE on RubyDoc Servers

The "major malicious attack" that targeted RubyGems in May 2026 was the work of a swarm of OpenAI agents, according to a new report published by researchers Spencer Kitts, Thomas Larsen, and Sydney Von Arx.

On May 12, Maciej Mensfeld, senior product manager for software supply chain security at Mend.io, disclosed details of a coordinated cyber attack that targeted the package manager for the Ruby programming language with hundreds of junk gems, prompting the maintainers to suspend new user sign-ups for about four days.

In a follow-up analysis, Socket highlighted a campaign dubbed GemStuffer that involved a cluster of more than 150 gems that used the package registry as a data exfiltration channel and staged public data scraped from U.K. local government democratic services portals. At that time, the software supply chain security company noted the activity shares the "same abuse pattern" as the broader RubyGems spam-publishing incident.

"It's not clear what exactly the end goals are, as the information appears to be publicly accessible anyway," The Hacker News reported back then.

The latest findings, which were first reported by The Wall Street Journal, indicate these events were propelled by a cluster of OpenAI agents, with the earliest package uploaded to RubyGems on May 5, 2026, before more than 2,000 packages were submitted between May 11 and 12, 2026. These efforts were followed by the agents publishing five more packages between May 26 and 27, 2026, and another 83 packages on June 18, 2026.