CVE-2026-45227 heymrun CVE debrief

Who should care

Users of Heym before version 0.0.21 should be aware of this vulnerability and take immediate action to update to a patched version. Security teams and administrators responsible for systems utilizing Heym should prioritize patching and monitor for potential exploitation attempts.

Technical summary

The vulnerability exists in the custom Python tool executor of Heym, allowing attackers to bypass sandbox restrictions by using object-graph introspection primitives. Attackers can recover the unrestricted __import__ function, import blocked modules such as os and subprocess, and access inherited backend environment variables containing sensitive information like database credentials and encryption keys.

Defensive priority

High

Recommended defensive actions

• Update Heym to version 0.0.21 or later
• Restrict access to sensitive environment variables
• Monitor for suspicious activity in Heym workflows
• Implement additional security controls for Python tool execution
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance
• Plan vendor-supported updates or mitigations through normal change control where exposure is confirmed

Evidence notes

The CVE record was published on 2026-05-12T22:16:38.260Z and was last modified on 2026-07-14T21:16:55.413Z. The NVD entry is currently Deferred. Multiple sources, including Vulncheck and the NVD, provide information about this vulnerability. The vulnerability allows authenticated workflow authors to bypass sandbox restrictions using Python introspection techniques, potentially leading to arbitrary host command execution as the backend service user. Evidence is limited, and defenders should verify the vulnerability's existence and scope. No additional information is available beyond the CVE record and NVD entry.

Official resources