CVE-2026-67540

Private workflow templates could be read by another tenant

Heym · Heym agent workflow templates

First documented disclosure · Review checkpoint

Summary

The single-template read path omitted the visibility checks used by the list view. Template contents and sharing metadata could be disclosed.

Severity and exploitation evidence

Medium · 6.5/10 · CVSS 3.1. Severity source.

Exploitation not established: The reviewed advisory does not report malicious exploitation.

Exploitation evidence source

Technical severity is not a measure of observed attacks or of risk to your deployment. Attempts, demonstrations, and successful compromise retain the qualifications in the source.

How the weakness works

The single-template read path omitted the visibility checks used by the list view.

Conditions required

An authenticated user had another template's identifier.

Potential impact

Template contents and sharing metadata could be disclosed.

Affected versions and configurations

Before 0.0.70.

Fix and mitigation status

0.0.70 according to the November CNA. The July advisory listed no fixed release.

Practical next steps

Upgrade Heym and verify access to private templates across tenants.

Operating lesson

Apply authorization and isolation to every backend path that can act on behalf of an agent.

Evidence and limits

The July advisory lists versions through 0.0.58 and no patched release. The November CNA identifies 0.0.70 as corrected. The public disclosure was on 2026-07-04. The CVE record was published on 2026-11-11.

Sources