CVE-2026-61681: Hatchet SSRF Vulnerability

MODERATE
Advisory Identifier: GHSA-fjwv-jf2v-j499
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CVSS 4.1
CWE-918
Published
Advisory Summary

CVE-2026-61681 is a MODERATE (CVSS 4.1) ssrf vulnerability (CWE-918: Server-Side Request Forgery (SSRF)) affecting Hatchet libraries in the Go ecosystem. The issue involves ssrf via unsigned unsubscribeurl in sns unsubscribeconfirmation handler. Remediation is available by upgrading affected packages to version 0.91.1.

CVE-2026-61681 at a Glance

CVE Identifier CVE-2026-61681
GHSA Identifier GHSA-fjwv-jf2v-j499
Severity MODERATE
CVSS v3.1 Base Score 4.1
CWE Classification CWE-918: Server-Side Request Forgery (SSRF)
Affected Product Hatchet
Package Ecosystem Go
Published Date
Last Updated

Security Impact

CVSS: 4.1

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

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

How to Fix CVE-2026-61681

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.

hatchet-dev/hatchet fixed: 0.91.1 
Upgrade 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 hatchet-dev/hatchet

How to Check if You Are Affected

To determine whether your application is affected by CVE-2026-61681, inspect your project dependencies for Hatchet:

inspect dependencies for 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-918: Server-Side Request Forgery (SSRF), where the web server receives a url or similar request from an upstream component and retrieves the contents of this url, but it does not sufficiently ensure that the request is being sent to the expected destination. 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 SNS `UnsubscribeConfirmation` handler in `internal/integrations/ingestors/sns/sns.go` makes an unvalidated `http.Get()` call to `payload.UnsubscribeURL` without any URL restriction. Because `UnsubscribeURL` is intentionally excluded from the `BuildSignature()` signed field list, an attacker can replace this field in a legitimately AWS-signed message with an arbitrary internal URL, bypassing the `VerifyPayload()` signature check entirely and triggering a Server-Side Request Forgery (SSRF) against internal infrastructure — including the EC2 Instance Metadata Service (IMDS) at `169.254.169.254`. ### Impact This is a Server-Side Request Forgery (SSRF) vulnerability. An attacker with a Hatchet account and an AWS Free Tier account can: - Reach the EC2 IMDS endpoint and retrieve IAM temporary credentials if Hatchet is deployed on AWS - Port-scan and probe internal services not exposed to the internet - Access internal HTTP APIs (e.g., Kubernetes API server, internal dashboards) from the Hatchet server's network context

CVE-2026-61681 Affected Hatchet Versions

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

References

GitHub Advisory / Wiki ADVISORY
https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-fjwv-jf2v-j499
NVD — CVE-2026-61681 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-61681
Security Fix Commit FIX COMMIT
https://github.com/hatchet-dev/hatchet/commit/2d211bce16e5022afaf95780de82dc30e0bcba98
Hatchet Source Repository REPOSITORY
https://github.com/hatchet-dev/hatchet

Frequently Asked Questions

What is CVE-2026-61681?
CVE-2026-61681 is a security vulnerability in Hatchet involving SSRF via Unsigned UnsubscribeURL in SNS UnsubscribeConfirmation Handler under CWE-918: Server-Side Request Forgery (SSRF).
Which Hatchet versions are affected?
Affected versions include releases prior to 0.91.1 across affected packages: hatchet-dev/hatchet.
What version fixes CVE-2026-61681?
Upgrading to 0.91.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is hatchet-dev/hatchet affected?
Yes, 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-2026-61681?
CVE-2026-61681 has a CVSS v3.1 base score of 4.1 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N.
What CWE is associated with CVE-2026-61681?
CVE-2026-61681 is classified under CWE-918: Server-Side Request Forgery (SSRF) (The web server receives a URL or similar request from an upstream component and retrieves the contents of this URL, but it does not sufficiently ensure that the request is being sent to the expected destination.).
How can I check Go dependencies for CVE-2026-61681?
Run the dependency tree command: 'inspect dependencies for 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-fjwv-jf2v-j499",
  "modified" : "2026-09-22T20:34:12Z",
  "published" : "2026-09-22T20:34:12Z",
  "aliases" : [ "CVE-2026-61681" ],
  "summary" : "Hatchet: SSRF via Unsigned UnsubscribeURL in SNS UnsubscribeConfirmation Handler",
  "details" : "### Summary\n  The SNS `UnsubscribeConfirmation` handler in `internal/integrations/ingestors/sns/sns.go` makes an unvalidated\n  `http.Get()` call to `payload.UnsubscribeURL` without any URL restriction. Because `UnsubscribeURL` is intentionally\n  excluded from the `BuildSignature()` signed field list, an attacker can replace this field in a legitimately\n  AWS-signed message with an arbitrary internal URL, bypassing the `VerifyPayload()` signature check entirely and\n  triggering a Server-Side Request Forgery (SSRF) against internal infrastructure — including the EC2 Instance Metadata\n  Service (IMDS) at `169.254.169.254`.\n\n ### Impact\n\n  This is a Server-Side Request Forgery (SSRF) vulnerability. An attacker with a Hatchet account and an AWS Free Tier\n  account can:\n\n  - Reach the EC2 IMDS endpoint and retrieve IAM temporary credentials if Hatchet is deployed on AWS\n  - Port-scan and probe internal services not exposed to the internet\n  - Access internal HTTP APIs (e.g., Kubernetes API server, internal dashboards) from the Hatchet server's network\n  context",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "Go",
      "name" : "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-fjwv-jf2v-j499"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-61681"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/hatchet-dev/hatchet/commit/2d211bce16e5022afaf95780de82dc30e0bcba98"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/hatchet-dev/hatchet"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-22T20:34:12Z",
    "nvd_published_at" : "2026-09-21T16:17:09Z"
  }
}