OAuth2 State Parameter Not Generated - "Insufficient parameters for OAuth2 callback" Error

[classTheTester]

Describe the problem/error/question
n8n OAuth2 implementation is not generating the required 'state' parameter when initiating OAuth2 flows, causing all OAuth2 connections to fail. This affects HubSpot and potentially all other OAuth2-based integrations.
What is the error message (if any)?
Error: Insufficient parameters for OAuth2 callback.

▼ More details
Received following query parameters: {"code":"na3-9cb2-2276-40ec-aa4b-6313eb4513da"}

Failed to connect. The window can be closed now.
Please share your workflow/screenshots/recording
This occurs when attempting to create any OAuth2 credential (not workflow-specific). Steps to reproduce:

Go to Credentials → Add Credential → HubSpot OAuth2
Enter Client ID and Client Secret
Click "Connect"
Authorize in HubSpot
Error appears on callback

When manually testing the OAuth2 flow by adding &state=test123 to the authorization URL, HubSpot correctly returns both parameters:
https://n8n-zkkxp-u32583.vm.elestio.app/rest/oauth2-credential/callback?code=na3-3a20-d2aa-4f89-9786-7435cbc99902&state=test123
This confirms n8n is not generating the state parameter in the initial authorization request.
Share the output returned by the last node
N/A - This is a credential creation issue, not a workflow execution issue.
Debug info
core

n8nVersion: 1.102.4
platform: docker (self-hosted)
nodeJsVersion: 22.17.0
database: postgres
executionMode: scaling (single-main)
concurrency: -1
license: enterprise (production)

storage

success: all
error: all
progress: false
manual: true
binaryMode: filesystem

pruning

enabled: true
maxAge: 168 hours
maxCount: 10000 executions

client

userAgent: mozilla/5.0 (windows nt 10.0; win64; x64) applewebkit/537.36 (khtml, like gecko) chrome/138.0.0.0 safari/537.36
isTouchDevice: false
Generated at: 2025-07-23T18:12:09.854Z

Additional context: Running on Elestio-hosted instance at n8n-zkkxp-u32583.vm.elestio.app. This appears to be a configuration issue with the OAuth2 state parameter generation.

[Joffcom]

Hey @classTheTester,

Thank you for reaching out! We’ve received your issue and are looking into it. To help us track this internally, we’ve created a Linear ticket with the reference: "GHC-3285".

We’ll keep you updated as we make progress, but if you have any additional details or context to share, feel free to add them here - it’s always helpful!

Thanks for your patience and for bringing this to our attention.

[Joffcom]

Thanks for reporting this issue! We’ve attempted to reproduce the problem, but unfortunately, we weren’t able to replicate it. It’s possible there was some environmental or other variable that prevented us from seeing the same behavior.

I have just given this a go with Hubspot as the steps suggest and this has worked for me, Do you have any more information on how you have n8n deployed?

If you’re still encountering this issue, please provide any additional details or steps to reproduce it, and we’d be happy to investigate further. Thanks for your understanding!

[classTheTester]

Thanks for getting back to me.
I've restructured the workflow to better handle managing multiple client HubSpot accounts at the same time and created an HTML form that links to my app's installation URL (respond to webhook).
Do you know how to manually append the state parameter when users click the "Install App" button? All the other parameters are being appended correctly when the user clicks the link.
I understand this issue is likely caused by not using HubSpot's native node, but there must be a way to work around this state parameter problem - perhaps by adding it manually?

[Joffcom]

Hey @classTheTester,

It gets tricky and depending on the user type there could be a license issue as well. As we don't have more info on how to actually reproduce this I am going to close this for now as it sounds more like a support issue which would be better suited to the forum.

[sjanaX01]

@Joffcom I am also found the same issue when I try to doing login via Oauth2, I deploy n8n from myself using cloudflare tunnel with https connection but till then I got this error

[carlosguzu]

I'm having the same issue @sjanaX01, im using ngrok instead and its the same, have you got any solution to this?

[sjanaX01]

@carlosguzu Insted I don't have any solution to this issue I host this locally but I connect this throgut cloudflare tunnel with SSL certification. I hope the core member can solve this issue.

[salzig]

@sjanaX01 and @carlosguzu did you use an external "link" (generated somewhere), instead of the one provided within the credentials dialog?

Edit: Had the same Problem connecting with Discord. Discord provides a "builder"/"generator" for an invite link, but that would always fail. Using the "Connect" button within the credentials dialog worked.

[carlosguzu]

@salzig in my case i was trying to set it up using ngrok and there wasnt a external link, i try using OAuth Redirect URL (that were the one i got from ngrok and previously declared on my docker file) and faced this issue. I ended up creating an app on google cloud and stuff for the credentials and same with slack, how weird local version dont have such option?

[sjanaX01]

@salzig yes I am using cloudflare tunnel with my local deployment