OpenCode Says Breach Affected 1.4% of Console Users With Linked AI Providers
Summary
OpenCode says an ongoing breach affected 1.4% of Console users with linked Anthropic, OpenAI, or Google providers; the cause and accessed data remain undisclosed. StepSecurity advises inventorying installations, checking credentials, rotating keys, and reviewing usage.
Key points
- OpenCode attributes the breach to a large-scale “distillation attack” and says 1.4% of Console users were affected.
- OpenCode says the affected users had linked external providers; it says the breach did not affect all users who installed the OpenCode CLI.
- The vendor says it emailed affected users on October 18, 2026. It describes the incident as ongoing and has not disclosed a root cause or what data was accessed.
- OpenCode stores linked provider credentials in auth.json on developer machines; StepSecurity advises treating listed credentials as potentially affected until users confirm their status with OpenCode.
- Recommended response includes rotating linked Anthropic, OpenAI, or Google API keys and checking provider usage dashboards for unrecognized requests.
- StepSecurity’s Dev Machine Guard can inventory OpenCode installations; its enterprise console also provides device and user listings for incident response.
Article Details
- Defense Focus
- Identify developer machines running OpenCode, determine whether linked provider credentials may be affected, and reduce risk by rotating those credentials and reviewing provider usage.
- Detection Methods
- Search developer machines for the OpenCode binary and its configuration and data directories.
- Use Dev Machine Guard to scan machines for OpenCode and review its reported version, binary path, and configuration directory.
- Inspect OpenCode's auth.json file to identify linked providers; treat listed provider credentials as potentially affected until the user's status is confirmed.
- Check for OpenCode's incident notification email and review linked providers' usage dashboards for unexpected requests.
- Data Sources
- Developer-machine inventory, including OpenCode binary paths, versions, and configuration directories
- OpenCode auth.json files on macOS, Linux, and Windows
- OpenCode incident notification emails
- Anthropic, OpenAI, and Google provider usage dashboards
- Platforms
- macOS
- Windows
- Linux
- Defensive Actions
- Identify all machines and users with OpenCode installed; use Dev Machine Guard for fleet-wide inventory where available.
- For each OpenCode user, check for the vendor's incident notification and determine which providers are linked.
- Rotate API keys linked to OpenCode or OpenCode Console, as recommended by the article.
- Review provider usage dashboards for requests the developer did not make.
- Do not use the installed OpenCode version alone to determine impact; the article says affected versions have not been published.
Vendors
AnthropicConsole users, specifically those who had external AI providers linked. The providers named are Anthropic, OpenAI, and Google.Googlespecifically those who had external AI providers linked. The providers named are Anthropic, OpenAI, and Google.OpenAIusers, specifically those who had external AI providers linked. The providers named are Anthropic, OpenAI, and Google.OpenCodeOn October 18, 2026, OpenCode, the open source AI coding agent, disclosed a security breach tied to what it calls a large scale distillation attack. OpenCode says the breach affected 1.4% of OpenCode Console users,StepSecurityIf you are not a StepSecurity customer, here is how to find OpenCode in your environment and respond. Both ways of finding it are free.
Products
OpenCodeOn October 18, 2026, OpenCode, the open source AI coding agent, disclosed a security breach tied to what it calls a large scale distillation attack. OpenCode says the breach affected 1.4% of OpenCode Console users,OpenCode Consoletied to what it calls a large scale distillation attack. OpenCode says the breach affected 1.4% of OpenCode Console users, specifically those who had external AI providers linked. The providers named are Anthropic,Threat CenterStepSecurity customers can answer "who has OpenCode?" from the console without asking developers to run anything, and the incident is already tracked in the Threat Center.