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Hatchet allows cross-tenant write/DoS to other tenants' workers via Dispatcher gRPC UpsertWorkerLabels and Unsubscribe

Moderate severity GitHub Reviewed Published Jun 30, 2026 in hatchet-dev/hatchet • Updated Aug 28, 2026

Package

gomod github.com/hatchet-dev/hatchet (Go)

Affected versions

>= 0.40.0, < 0.91.2

Patched versions

0.91.2

Description

Summary

A cross-tenant write / DoS vulnerability in the Hatchet Dispatcher gRPC service allows any holder of a normal tenant-scoped API token (the lowest credential Hatchet issues — an OWNER of a brand-new tenant) to overwrite the affinity labels of, or disconnect from the dispatcher, any worker UUID belonging to any other tenant on the same Hatchet instance. The two affected RPCs — Dispatcher/UpsertWorkerLabels and Dispatcher/Unsubscribe — read the caller's tenant from the bearer-token context only for analytics and response shaping, and never use it to authorise the worker_id from the request body.

Impact

This CVE requires the attacker to successfully guess the target UUID.
Who is impacted. Any Hatchet deployment that hosts more than one tenant on the same instance:

  • Hatchet Cloud (multi-tenant SaaS) — every tenant is exposed to every other tenant.
  • Self-hosted Hatchet with multiple internal teams / business units sharing one instance — each team is exposed to every other team on the box.
  • Any deployment where a single tenant's API token can be obtained by an attacker (e.g. a leaked low-privilege CI token from a single tenant). One token is enough to attack every other tenant on the same instance.

Single-tenant self-hosted deployments are unaffected in practice (the "victim" and "attacker" tenants would be the same).

References

@grutt grutt published to hatchet-dev/hatchet Jun 30, 2026
Published to the GitHub Advisory Database Aug 28, 2026
Reviewed Aug 28, 2026
Last updated Aug 28, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Network
Attack complexity
Low
Privileges required
Low
User interaction
None
Scope
Changed
Confidentiality
None
Integrity
Low
Availability
Low

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L

EPSS score

Exploit Prediction Scoring System (EPSS)

This score estimates the probability of this vulnerability being exploited within the next 30 days. Data provided by FIRST.
(19th percentile)

Weaknesses

Authorization Bypass Through User-Controlled Key

The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data. Learn more on MITRE.

Missing Authorization

The product does not perform an authorization check when an actor attempts to access a resource or perform an action. Learn more on MITRE.

CVE ID

CVE-2026-54746

GHSA ID

GHSA-8x7x-83cf-c3pg

Source code

Credits

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