Description

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, api-contracts/openapi/paths/v1/workflow-runs/workflow_run.yaml defines the GET /api/v1/stable/durable-tasks/{durable-task} endpoint implemented by listDurableEventLog without requiring the target tenant as a parent resource, allowing an authenticated user who obtains another tenant's durable task UUID to read that task's event log. Disclosed data can include task display names, workflow identifiers, user messages, wait conditions, branching logic, and timing information. This issue is fixed in version 0.91.1.

Executive Summary

Technical Details

Mitigations

References

Additional Metadata

{
  "score": "6.3",
  "pubDate": "2026-09-21T16:17:10.737Z",
  "pubdate": "2026-09-21T16:17:10.737Z",
  "executiveSummary": "Hatchet contains an Insecure Direct Object Reference (IDOR) vulnerability within the durable task event logging API, specifically affecting versions prior to 0.91.1.\nThe vulnerability exists because the GET /api/v1/stable/durable-tasks/{durable-task} endpoint fails to validate that the requested resource belongs to the authenticated user's tenant.\nThis authorization bypass allows an authenticated attacker to access sensitive event logs belonging to other tenants by providing a valid durable task UUID.\nThe impact is significant, as it exposes confidential metadata including workflow identifiers, branching logic, timing information, and user-defined payloads.\nSuccessful exploitation requires the attacker to be authenticated within the Hatchet platform and possess the target's durable task UUID.\nThe vulnerability represents a failure in resource-level access control, potentially leading to unauthorized information disclosure of proprietary business workflows and task execution state.",
  "technicalDetails": "The vulnerability is located in the implementation of the listDurableEventLog function, which is exposed via the API endpoint defined in api-contracts/openapi/paths/v1/workflow-runs/workflow_run.yaml.\nThe root cause is a lack of hierarchical authorization checking; the endpoint performs a lookup of the requested resource using the {durable-task} identifier without verifying that the resource is associated with the authenticated user's tenant context.\nNormally, in a multi-tenant application, resource access should be constrained by a tenant identifier passed in the session or a scoping check that validates the resource-tenant relationship before retrieving data.\nThe attack flow begins with an authenticated attacker gaining access to a durable task UUID, potentially through secondary reconnaissance or information leakage.\nBy issuing a GET request to /api/v1/stable/durable-tasks/{durable-task}, the attacker bypasses the expected tenant boundary restriction.\nThe backend service, upon receiving the request, maps the {durable-task} UUID directly to the database entry and returns the event log contents to the user.\nSince the check for the target tenant as a parent resource is omitted, the application treats the UUID as globally accessible to any authenticated session.\nThe information disclosed is highly sensitive and includes task display names, internal workflow identifiers, user messages, wait conditions, and branching logic.\nThis data can be leveraged to map out the internal infrastructure and logic of the target organization's automated workflows, providing an attacker with significant reconnaissance data for further attacks against the target's internal services or workflows.\nThe vulnerability is limited to authenticated users; however, in many SaaS environments, this scope includes any user with valid platform credentials, regardless of their specific tenant association.\nThe issue is specific to versions of Hatchet prior to 0.91.1."
}