GHSA-5m98-cgcr-xx3q: Npm/n8n vulnerability
Impact
The GitHub Trigger generated a signing secret when it registered a webhook and verified X-Hub-Signature-256 on each delivery. When GitHub answered the create request with a 422 because a webhook for the URL already existed, the node adopted the remote hook but kept only its id and events, discarding the secret it had generated. Deliveries to that workflow's webhook URL were then accepted from anyone. The patch re-fetches the existing hook by its stored id, re-applies the signing secret, and makes verification fail closed when no secret is stored.
Patches
The issue has been fixed in n8n versions 1.123.76, 2.37.7, and 2.38.2. Users should upgrade to one of these versions or later to remediate the vulnerability.
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Deactivate and reactivate any GitHub Trigger workflows to force a fresh webhook registration with a new secret, provided the remote GitHub hook has been deleted first so that the 422 reuse path is not taken again. - Restrict network access to the n8n webhook endpoint to GitHub's published IP ranges only. - Audit GitHub Trigger workflow static data for entries that contain a webhookId but no webhookSecret, and treat those workflows as unprotected until reactivated successfully.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 1.123.76 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 1.123.76 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.37.7 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.38.2 - Compensating control
Restrict network access to the n8n webhook endpoint to GitHub's published IP ranges only.
- Operational
Audit GitHub Trigger workflow static data for entries that contain a `webhookId` but no `webhookSecret`, and treat those workflows as unprotected until reactivated successfully.
- Operational
Deactivate and reactivate any GitHub Trigger workflows to force a fresh webhook registration with a new secret; ensure the remote GitHub hook has been deleted first so that the 422 reuse path is not taken again.
Event History
Frequently Asked Questions
Which workflows are exposed to unauthenticated webhook deliveries?
GitHub Trigger workflows are exposed when n8n receives a 422 response during webhook creation because a hook for the same URL already exists. In that path, n8n adopts the existing remote hook without retaining a signing secret, allowing deliveries to that workflow URL from anyone.
What versions contain the fix?
The issue is fixed in n8n 1.123.76, 2.37.7, and 2.38.2, as well as later versions. Upgrade to one of those versions or later to remediate it.
What can be done if an upgrade cannot happen immediately?
Deactivate and reactivate affected GitHub Trigger workflows after deleting the corresponding remote GitHub hook, so registration creates a fresh hook with a new secret rather than taking the 422 reuse path. Restricting access to the n8n webhook endpoint to GitHub's published IP ranges is also a temporary mitigation.
How can administrators identify potentially affected workflows?
Audit GitHub Trigger workflows, particularly those whose webhook registration may have encountered a 422 because the URL already had a GitHub hook. Review the remote GitHub hooks associated with those workflow webhook URLs.