n8n: Unauthenticated Endpoint Allows Cancellation of Any User's Active Test Webhook
## Impact The `DELETE /${restEndpoint}/test-webhook/:id` route is registered before the authentication middleware is applied, allowing any unauthenticated network caller who knows a workflow ID to cancel that workflow's active test webhook registration. The impact is limited to disrupting in-progress test sessions. Production webhooks, persistent workflow state, and stored data are not affected. ## Patches Users should upgrade to the patched version once available to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict network access to the n8n instance to fully trusted users only. - Place the n8n instance behind a reverse proxy or firewall that requires authentication before reaching the REST API. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2026-65014US | medium5.3OT elevated | — | ||
n8n before 2.28.0 (and before 2.27.4 on the 2.27.x branch) registers the DELETE /${restEndpoint}/test-webhook/:id endpoint before authentication middleware is applied, allowing any… | ||||
references
External citations — patches, advisories, analysis.
- https://github.com/n8n-io/n8nPACKAGE
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.27.4WEB
- https://github.com/n8n-io/n8n/releases/tag/n8n@2.28.0WEB
- https://github.com/n8n-io/n8n/security/advisories/GHSA-33q9-f52j-gc75WEB
- https://nvd.nist.gov/vuln/detail/CVE-2026-65014ADVISORY
- https://www.vulncheck.com/advisories/n8n-before-authentication-bypass-via-test-webhookWEB
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