N8n: Duplicate Advisory: Unauthenticated Endpoint Allows Cancellation of Any User's Active Test Webhook
n8n versions before 2.28.0 (and before 2.27.4 on the 2.27.x branch) expose an unauthenticated DELETE endpoint that allows cancellation of any user's active test webhook by knowing the workflow ID. This vulnerability only affects test webhook sessions and does not impact production webhooks, persistent workflow state, or stored data. The advisory is a duplicate and has been withdrawn in favor of GHSA-33q9-f52j-gc75.
AI Analysis
Technical Summary
The vulnerability in n8n prior to version 2.28.0 (and 2.27.4 on the 2.27.x branch) arises because the DELETE /${restEndpoint}/test-webhook/:id endpoint is registered before authentication middleware is applied. This allows an unauthenticated attacker who knows a workflow ID to cancel that workflow's active test webhook registration. The impact is limited to disruption of in-progress test webhook sessions only, without affecting production webhooks or stored data.
Potential Impact
An unauthenticated attacker can cancel active test webhook sessions for any workflow if they know the workflow ID. This causes disruption to testing activities but does not compromise production webhooks, persistent workflow state, or stored data. There is no indication of data loss or privilege escalation.
Mitigation Recommendations
A fix is available in n8n version 2.28.0 and 2.27.4 for the 2.27.x branch, where the endpoint is properly protected by authentication middleware. Users should upgrade to these versions or later to remediate this issue. Since this advisory is a duplicate and withdrawn, consult the original advisory GHSA-33q9-f52j-gc75 for official vendor guidance.
N8n: Duplicate Advisory: Unauthenticated Endpoint Allows Cancellation of Any User's Active Test Webhook
Description
n8n versions before 2.28.0 (and before 2.27.4 on the 2.27.x branch) expose an unauthenticated DELETE endpoint that allows cancellation of any user's active test webhook by knowing the workflow ID. This vulnerability only affects test webhook sessions and does not impact production webhooks, persistent workflow state, or stored data. The advisory is a duplicate and has been withdrawn in favor of GHSA-33q9-f52j-gc75.
CVSS v4.0
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability in n8n prior to version 2.28.0 (and 2.27.4 on the 2.27.x branch) arises because the DELETE /${restEndpoint}/test-webhook/:id endpoint is registered before authentication middleware is applied. This allows an unauthenticated attacker who knows a workflow ID to cancel that workflow's active test webhook registration. The impact is limited to disruption of in-progress test webhook sessions only, without affecting production webhooks or stored data.
Potential Impact
An unauthenticated attacker can cancel active test webhook sessions for any workflow if they know the workflow ID. This causes disruption to testing activities but does not compromise production webhooks, persistent workflow state, or stored data. There is no indication of data loss or privilege escalation.
Mitigation Recommendations
A fix is available in n8n version 2.28.0 and 2.27.4 for the 2.27.x branch, where the endpoint is properly protected by authentication middleware. Users should upgrade to these versions or later to remediate this issue. Since this advisory is a duplicate and withdrawn, consult the original advisory GHSA-33q9-f52j-gc75 for official vendor guidance.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- GHSA-h9fm-xcv2-qfw3
- Osv Schema Version
- 1.4.0
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- MODERATE
- Cvss Version
- 4.0
Threat ID: 6a6150c69c2644c7f8d9fc89
Added to database: 07/22/2026, 23:22:46 UTC
Last enriched: 07/22/2026, 23:25:03 UTC
Last updated: 07/23/2026, 02:51:54 UTC
Views: 4
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