CVE-2026-63342 Hatchet: Cross-Tenant Durable Task Event Log Disclosure via Missing Authorization Check
An authenticated user can read another tenant's durable task event logs by guessing UUIDs, exposing workflow details and user messages.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-63342?
CVE-2026-63342 is a medium-severity missing authorization vulnerability in hatchet-dev hatchet, published on 21 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official 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.
Weakness: CWE-863
Which versions are affected by CVE-2026-63342?
3 open source packages ship an affected version, including github.com/hatchet-dev/hatchet.
| Package | Affected | Fixed in |
|---|---|---|
github.com/hatchet-dev/hatchet Go | All versions | 0.91.1 |
github.com/hatchet-dev/hatchet Go | All versions | 0.91.1 |
github.com/hatchet-dev/hatchet Go | All versions | 0.91.1 |
How do I fix CVE-2026-63342?
Upgrade github.com/hatchet-dev/hatchet to 0.91.1 or later.
Upgrade, and check permissions on every request on the server, not only in the interface. More about Missing authorization.
Is CVE-2026-63342 being exploited?
There is no known exploitation of CVE-2026-63342 in the wild and no public exploit code.
Sources
Also known as GHSA-g26x-m427-f48f, GO-2026-6567.