# CVE-2026-61681: Hatchet: SSRF via Unsigned UnsubscribeURL in SNS UnsubscribeConfirmation Handler

> An authenticated user can trigger Server-Side Request Forgery in Hatchet by manipulating the SNS UnsubscribeURL, potentially exposing internal data and IAM credentials.

- **Severity:** Medium 4.1 (`CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** An administrator
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 21 Sep 2026
- **Updated:** 24 Sep 2026
- **Also known as:** GHSA-fjwv-jf2v-j499, GO-2026-6565

## What is CVE-2026-61681?

CVE-2026-61681 is a medium-severity server-side request forgery vulnerability in hatchet-dev hatchet, published on 21 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.

### Official description

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, the SNS UnsubscribeConfirmation handler in internal/integrations/ingestors/sns/sns.go calls http.Get() on payload.UnsubscribeURL after VerifyPayload() even though BuildSignature() excludes UnsubscribeURL, allowing an authenticated Hatchet tenant to replace that field in an otherwise valid AWS-signed message with an internal URL. The server-side request can reach EC2 Instance Metadata Service, internal services, and internal HTTP APIs, potentially exposing IAM credentials or network-accessible data and functionality. This issue is fixed in version 0.91.1.

Weakness: CWE-918 (Server-Side Request Forgery)

## Which versions are affected by CVE-2026-61681?

3 open source packages ship an affected version, including hatchet-dev/hatchet and github.com/hatchet-dev/hatchet.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `hatchet-dev/hatchet` | Go | All versions | 0.91.1 |
| `hatchet-dev/hatchet` | Go | All versions | 0.91.1 |
| `github.com/hatchet-dev/hatchet` | Go | All versions | 0.91.2 |

## How do I fix CVE-2026-61681?

Upgrade hatchet-dev/hatchet to 0.91.1 or later.

## Is CVE-2026-61681 being exploited?

There is no known exploitation of CVE-2026-61681 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-61681 and fix it if it is affected.

What it is: CVE-2026-61681 is a medium-severity server-side request forgery vulnerability in hatchet-dev hatchet, published on 21 Sep 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-61681 in the wild and no public exploit code.

Affected packages and fixed versions:
- hatchet-dev/hatchet (Go): affected all versions; fixed in 0.91.1
- hatchet-dev/hatchet (Go): affected all versions; fixed in 0.91.1
- github.com/hatchet-dev/hatchet (Go): affected all versions; fixed in 0.91.2

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-61681/ (Markdown: https://insights.sbomify.com/CVE-2026-61681/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-61681
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-61681
- OSV: https://osv.dev/vulnerability/CVE-2026-61681

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-61681/
Summaries are generated and may contain mistakes; the official description above is the record.