CVE-2026-63342: Hatchet Cross-Tenant Durable Task Event Log Vulnerability

MODERATE
Advisory Identifier: GHSA-g26x-m427-f48f
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CVSS 6.3
CWE-863
Published
Advisory Summary

CVE-2026-63342 is a MODERATE (CVSS 6.3) cross-tenant durable task event log vulnerability (CWE-863: Incorrect Authorization) affecting Hatchet libraries in the Go ecosystem. The issue involves cross-tenant durable task event log disclosure via missing authorization check. Remediation is available by upgrading affected packages to version 0.91.1.

CVE-2026-63342 at a Glance

CVE Identifier CVE-2026-63342
GHSA Identifier GHSA-g26x-m427-f48f
Severity MODERATE
CVSS v3.1 Base Score 6.3
CWE Classification CWE-863: Incorrect Authorization
Affected Product Hatchet
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 6.3

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

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

How to Fix CVE-2026-63342

To remediate this vulnerability, upgrade all affected 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: 0.91.1 
Upgrade github.com/hatchet-dev/hatchet to 0.91.1
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-2026-63342, inspect your project dependencies for Hatchet:

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

Analyze the terminal output to locate any version of Hatchet in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.91.1), 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-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In 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 The `GET /api/v1/stable/durable-tasks/{durable-task}` endpoint (`listDurableEventLog`) is missing tenant authorization validation, allowing any authenticated user to read durable task event logs from any tenant. ### Impact This CVE requires the attacker to successfully guess the target UUID. Any authenticated Hatchet user can read durable task event logs from any other tenant, exposing: - Task display names and workflow identifiers - User messages (may contain sensitive business data) - Wait conditions and branching logic - Timing information

CVE-2026-63342 Affected Hatchet Versions

1 component(s)
Fixed Versions:
0.91.1
Product / Package Ecosystem Affected Versions Fixed Version
github.com/hatchet-dev/hatchet
golang/github.com/hatchet-dev/hatchet
Go
< 0.91.1
0.91.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-g26x-m427-f48f
NVD — CVE-2026-63342 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-63342
Security Fix Commit FIX COMMIT
https://github.com/hatchet-dev/hatchet/commit/06c1fe43543e853ea98ecc2e6a575e2b8310bbeb
Hatchet Source Repository REPOSITORY
https://github.com/hatchet-dev/hatchet

Frequently Asked Questions

What is CVE-2026-63342?
CVE-2026-63342 is a security vulnerability in Hatchet involving Cross-Tenant Durable Task Event Log Disclosure via Missing Authorization Check under CWE-863: Incorrect Authorization.
Which Hatchet versions are affected?
Affected versions include releases prior to 0.91.1 across affected packages: github.com/hatchet-dev/hatchet.
What version fixes CVE-2026-63342?
Upgrading to 0.91.1 (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 0.91.1. Upgrade your dependency to 0.91.1 or later.
What is the CVSS score of CVE-2026-63342?
CVE-2026-63342 has a CVSS v3.1 base score of 6.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N.
What CWE is associated with CVE-2026-63342?
CVE-2026-63342 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check Go dependencies for CVE-2026-63342?
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-g26x-m427-f48f",
  "modified" : "2026-09-22T20:34:14Z",
  "published" : "2026-09-22T20:34:14Z",
  "aliases" : [ "CVE-2026-63342" ],
  "summary" : "Hatchet: Cross-Tenant Durable Task Event Log Disclosure via Missing Authorization Check",
  "details" : "### Summary\n\nThe `GET /api/v1/stable/durable-tasks/{durable-task}` endpoint (`listDurableEventLog`) is missing tenant authorization validation, allowing any authenticated user to read durable task event logs from any tenant.\n\n\n### Impact\nThis CVE requires the attacker to successfully guess the target UUID.\nAny authenticated Hatchet user can read durable task event logs from any other tenant, exposing:\n- Task display names and workflow identifiers\n- User messages (may contain sensitive business data)\n- Wait conditions and branching logic\n- Timing information",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "github.com/hatchet-dev/hatchet"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.91.1"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-g26x-m427-f48f"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-63342"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hatchet-dev/hatchet/commit/06c1fe43543e853ea98ecc2e6a575e2b8310bbeb"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hatchet-dev/hatchet"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-22T20:34:14Z",
    "nvd_published_at" : "2026-09-21T16:17:10Z"
  }
}