CVE-2026-59259 n8n vulnerability
n8n before versions 1.123.61, 2.27.4, and 2.28.1 contains a permission bypass vulnerability in external secrets handling caused by a mismatch between the static validation check and the runtime expression engine. An authenticated user with credential create or update permissions but without the externalSecret:list scope can embed external secret references into credentials in forms the static validation does not detect; these references resolve at workflow execution time, exposing secret values the user is not authorized to access. This issue only affects instances where an external secrets provider is configured and Advanced Permissions are in use.
Quick answer
n8n should be reviewed and updated if it matches the affected versions. The recommended fix is to apply the vendor-supported patched version or the mitigation steps below, then retest the public website with Fixnx.
Who is affected
Affected versions
- 2.28.0
Fixed versions
- Apply the latest vendor-supported patched version.
How to fix it
CVE-2026-59259 affects n8n and is rated medium. n8n before versions 1.123.61, 2.27.4, and 2.28.1 contains a permission bypass vulnerability in external secrets handling caused by a mismatch between the static validation check and the runtime expression engine. Fix this first on internet-facing or admin systems. The practical fix is to upgrade n8n to 1.123.61, 2.27.4, 2.28.1, or a later patched release, then verify the system is no longer exposed.
- Inventory every server, container, appliance, cluster, plugin, or device that uses n8n.
- Check the installed version and configuration against CVE-2026-59259 and the linked advisory.
- Apply the vendor fix: upgrade n8n to 1.123.61, 2.27.4, 2.28.1, or a later patched release.
- Limit workflow, credential, webhook, and external secret access to trusted users only.
- Disable or isolate the affected feature if you cannot update right away.
- Review workflow runs, credential changes, webhook hits, and external secret use for suspicious activity.
- Rotate secrets, rebuild affected systems, or reset sessions if you suspect compromise.
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Verify the fix
- Confirm n8n is running the patched version or the approved mitigation is active.
- Confirm affected public, admin, API, tunnel, or cluster access is limited to trusted users.
- Repeat the risky workflow or a safe test case and confirm the issue no longer appears.
- Review logs again after the fix for crashes, bypass attempts, file access, or suspicious changes.
- Save version, config, log, and scan evidence for your remediation record.
Related categories
Trusted references
FAQ
What is affected by CVE-2026-59259?
n8n versions listed as affected should be reviewed: 2.28.0.
What should I fix first?
Start with internet-facing sites, admin panels, login flows, plugins, themes, modules, packages, and systems that process user-controlled input or sensitive data.
How do I confirm the fix worked?
Apply the patched version or mitigation, clear caches where relevant, retest the affected workflow, and run a new Fixnx scan to verify public website exposure signals.
How are Fixnx security risk categories chosen?
Fixnx keeps one canonical risk page and assigns only broad, relevant categories such as ecosystem, technology area, or vulnerability class.