---
id: "CVE-2026-61687"
kind: "vulnerability"
aliases: ["CVE-2026-61687", "GHSA-phg3-3g28-wq9v", "GO-2026-6535"]
title: "Unauthenticated OAuth state CSRF via empty-state collision in ValidateOAuthState in github.com/hatchet-dev/hatchet"
severity: "high"
cvss: 7.1
epss: 0.00171
exploited: false
status: "open"
category: "runtime"
products: [{"name": "github.com/hatchet-dev/hatchet", "fixed": ["0.91.2"], "affected": "< 0.91.2", "ecosystem": "go"}]
ecosystems: ["go"]
tags: ["github-oauth", "google-oauth", "hatchet", "runtime", "self-hosted", "slack"]
not_affected_if: ["default-config", "oauth-disabled"]
published_at: "2026-09-21T16:17:09+00:00"
first_seen_at: "2026-10-23T19:13:08+00:00"
updated_at: "2026-10-23T21:45:51+00:00"
sources: [{"source": "govuln", "url": "https://pkg.go.dev/vuln/GO-2026-6535", "first_seen_at": "2026-10-23T19:13:08+00:00"}, {"source": "epss", "url": "https://api.first.org/data/v1/epss?cve=CVE-2026-61687", "first_seen_at": "2026-10-23T19:13:43+00:00"}, {"source": "nvd", "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-61687", "first_seen_at": "2026-10-23T19:35:23+00:00"}]
---

# Unauthenticated OAuth state CSRF via empty-state collision in ValidateOAuthState in github.com/hatchet-dev/hatchet

Hatchet's ValidateOAuthState clears the oauth_state_ session value to an empty string after a successful OAuth callback, then accepts an empty state parameter as a match. An unauthenticated attacker can bind a victim's Hatchet session to an attacker-controlled OAuth identity.

_Summary, check and fix written by a model from the sources; labelled as such._

## Affected

- go:github.com/hatchet-dev/hatchet affected < 0.91.2 fixed 0.91.2

## How to check

Check whether the deployed Hatchet version is below 0.91.2 (go.mod: github.com/hatchet-dev/hatchet).
Confirm whether auth.google.enabled, auth.github.enabled, or the Slack integration is turned on.

## Fix

Upgrade github.com/hatchet-dev/hatchet to 0.91.2 (the sources conflict: the description says 0.91.1).

## Timeline

- 2026-10-23T19:13:08+00:00 govuln https://pkg.go.dev/vuln/GO-2026-6535
- 2026-10-23T19:13:43+00:00 epss https://api.first.org/data/v1/epss?cve=CVE-2026-61687
- 2026-10-23T19:35:23+00:00 nvd https://nvd.nist.gov/vuln/detail/CVE-2026-61687

## From the sources

Hatchet is a platform for orchestrating background tasks, AI agents, and durable workflows at scale. Prior to 0.91.1, ValidateOAuthState clears the oauth_state_ session value to an empty string after a successful OAuth callback and later accepts an empty state parameter as equal, allowing an unauthenticated attacker to bind a victim's Hatchet session to an attacker-controlled OAuth identity. Exploitation requires the victim to have completed an OAuth flow in the current session and the deployment to enable auth.google.enabled, auth.github.enabled, or the Slack integration. This issue is fixed in version 0.91.1.

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_Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai_