CVE-2026-54746: Github.com/hatchet dev/hatchet Denial of Service Vulnerability

MODERATE
Advisory Identifier: GHSA-8x7x-83cf-c3pg
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CVSS 6.4
CWE-639 CWE-862
Published
Advisory Summary

CVE-2026-54746 is a MODERATE (CVSS 6.4) denial of service vulnerability (CWE-639: Authorization Bypass Through User-Controlled Key) affecting Github.com/hatchet dev/hatchet libraries in the Go ecosystem. The issue involves hatchet allows cross-tenant write/dos to other tenants' workers via dispatcher grpc upsertworkerlabels and unsubscribe. Remediation is available by upgrading affected packages to version 0.91.2.

CVE-2026-54746 at a Glance

CVE Identifier CVE-2026-54746
GHSA Identifier GHSA-8x7x-83cf-c3pg
Severity MODERATE
CVSS v3.1 Base Score 6.4
CWE Classification CWE-639: Authorization Bypass Through User-Controlled Key
Affected Product Github.com/hatchet dev/hatchet
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.4

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Changed (S:C)
Confidentiality None (C:N)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-54746

To remediate this vulnerability, upgrade all affected Github.com/hatchet dev/hatchet dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

github.com/hatchet-dev/hatchet fixed: 0.91.2 
Upgrade github.com/hatchet-dev/hatchet to 0.91.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for github.com/hatchet-dev/hatchet

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-54746, inspect your project dependencies for Github.com/hatchet dev/hatchet:

inspect dependencies for github.com/hatchet-dev/hatchet

Analyze the terminal output to locate any version of Github.com/hatchet dev/hatchet in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.91.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-639: Authorization Bypass Through User-Controlled Key, where 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. In Github.com/hatchet dev/hatchet, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### 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).

CVE-2026-54746 Affected Github.com/hatchet dev/hatchet Versions

1 component(s)
Fixed Versions:
0.91.2
Product / Package Ecosystem Affected Versions Fixed Version
github.com/hatchet-dev/hatchet
golang/github.com/hatchet-dev/hatchet
Go
≥ 0.40.0
< 0.91.2
0.91.2

References

GitHub Advisory / Wiki ADVISORY
https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-8x7x-83cf-c3pg
Security Fix Commit FIX COMMIT
https://github.com/hatchet-dev/hatchet/commit/591a30deb8b80f02eba7014997de387d710986c9
Github.com/hatchet dev/hatchet Source Repository REPOSITORY
https://github.com/hatchet-dev/hatchet

Frequently Asked Questions

What is CVE-2026-54746?
CVE-2026-54746 is a security vulnerability in Github.com/hatchet dev/hatchet involving Hatchet allows cross-tenant write/DoS to other tenants' workers via Dispatcher gRPC UpsertWorkerLabels and Unsubscribe under CWE-639: Authorization Bypass Through User-Controlled Key.
Which Github.com/hatchet dev/hatchet versions are affected?
Affected versions include releases prior to 0.91.2 across affected packages: github.com/hatchet-dev/hatchet.
What version fixes CVE-2026-54746?
Upgrading to 0.91.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is github.com/hatchet-dev/hatchet affected?
Yes, github.com/hatchet-dev/hatchet is affected in releases prior to 0.91.2. Upgrade your dependency to 0.91.2 or later.
What is the CVSS score of CVE-2026-54746?
CVE-2026-54746 has a CVSS v3.1 base score of 6.4 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L.
What CWE is associated with CVE-2026-54746?
CVE-2026-54746 is classified under CWE-639: 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.).
How can I check Go dependencies for CVE-2026-54746?
Run the dependency tree command: 'inspect dependencies for github.com/hatchet-dev/hatchet'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-8x7x-83cf-c3pg",
  "modified" : "2026-08-28T16:08:58Z",
  "published" : "2026-08-28T16:08:58Z",
  "aliases" : [ "CVE-2026-54746" ],
  "summary" : "Hatchet allows cross-tenant write/DoS to other tenants' workers via Dispatcher gRPC UpsertWorkerLabels and Unsubscribe",
  "details" : "### Summary\n\nA **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.\n\n\n### Impact\nThis CVE requires the attacker to successfully guess the target UUID. \n**Who is impacted.** Any Hatchet deployment that hosts more than one tenant on the same instance:\n- **Hatchet Cloud (multi-tenant SaaS)** — every tenant is exposed to every other tenant.\n- **Self-hosted Hatchet with multiple internal teams / business units sharing one instance** — each team is exposed to every other team on the box.\n- **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.\n\nSingle-tenant self-hosted deployments are unaffected in practice (the \"victim\" and \"attacker\" tenants would be the same).",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:L"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/hatchet-dev/hatchet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0.40.0"
      }, {
        "fixed" : "0.91.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-8x7x-83cf-c3pg"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hatchet-dev/hatchet/commit/591a30deb8b80f02eba7014997de387d710986c9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hatchet-dev/hatchet"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-639", "CWE-862" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-28T16:08:58Z",
    "nvd_published_at" : null
  }
}