n8n Vulnerable to RCE via Arbitrary File Write

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

9.9 · CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS

• CVE-2026-21877: 5.45% estimated exploitation activity in the next 30 days; percentile 92.75 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Impact n8n is affected by an authenticated Remote Code Execution (RCE) vulnerability. Under certain conditions, an authenticated user may be able to cause untrusted code to be executed by the n8n service. This could result in full compromise of the affected instance. Both self-hosted and n8n Cloud instances are impacted. Patches The issue has been resolved in n8n version 1.121.3. Users are advised to upgrade to this version or later to fully address the vulnerability. Workarounds If upgrading is not immediately possible, administrators can reduce exposure by disabling the Git node and limiting access for untrusted users. References - n8n documentation: Blocking access to nodes

Published by the source

6 Jan 2026, 17:48 UTC

Last modified by the source

3 Feb 2026, 03:16 UTC

Source last checked

26 Oct 2026, 12:41 UTC

1. Revision 3 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-v364-rw7m-3263

2. Revision 2 · amended · 24 Oct 2026

   Amended from osv record GHSA-v364-rw7m-3263

3. Revision 1 · created · 23 Oct 2026

   Published from ghsa record GHSA-v364-rw7m-3263

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# Patch Next advisory brief: CVE-2026-21877

Advisory: n8n Vulnerable to RCE via Arbitrary File Write
IDs: CVE-2026-21877, GHSA-v364-rw7m-3263
Record: https://patchnext.com/advisories/cve-2026-21877 (revision 3, source checked 26 Oct 2026, 12:41 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Critical (CVSS 9.9)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: n8n 1.121.3. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm n8n: affected >= 0.123.0, < 1.121.3; fixed in 1.121.3

## Suggested inspection (read-only)
- `npm ls n8n --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on n8n.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-v364-rw7m-3263 (GitHub-reviewed advisory GHSA-v364-rw7m-3263 lists affected ranges: npm n8n >=0.123.0 <1.121.3)
- Verified: https://osv.dev/vulnerability/GHSA-v364-rw7m-3263 (OSV record GHSA-v364-rw7m-3263 lists affected ranges: npm n8n >=0.123.0 <1.121.3 (fixed))

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