---
title: "CVE-2026-21877: n8n Vulnerable to RCE via Arbitrary File Write"
url: https://erroneo.us/security/cve/CVE-2026-21877/
description: "CVE-2026-21877 (n8n (npm)): n8n is an open source workflow automation platform. In versions 0.121.2 and below, an authenticated attacker may be able to…"
type: vulnerability-record
section: "Security Digest"
date_published: 2026-01-08
date_modified: 2026-01-08
publisher: erroneo.us
author: erroneo.us Security Desk
cve: "CVE-2026-21877"
kev: false
cvss: 10
epss: 0.05449
license: All rights reserved. Quote with attribution and a link.
---

# CVE-2026-21877: n8n Vulnerable to RCE via Arbitrary File Write

**Signal:** Critical, preconditions apply. Severe if exploited, but exploitation needs conditions that may not apply to you. (Computed from CISA KEV, EPSS and CVSS; not an editorial verdict.)

## Should you act?

- No confirmed exploitation. It is not in CISA’s KEV catalog and CISA’s SSVC assessment records no known exploitation. That can change quickly after a public write-up; re-check if you are affected.
- EPSS 5.4% , percentile 93: FIRST’s model estimates a 5.4% chance of exploitation activity in the next 30 days, higher than 93% of all scored CVEs (elevated). EPSS is a probability, not a verdict.
- Needs an account (low (any account)). Exposure depends on who can log in.
- Only applies if your dependency tree includes n8n (npm) >= 0.123.0, < 1.121.3, fixed in 1.121.3 . Check your lockfile, including transitive dependencies.

## What it is

n8n is an open source workflow automation platform. In versions 0.121.2 and below, an authenticated attacker may be able to execute malicious code using the n8n service. This could result in full compromise and can impact both self-hosted and n8n Cloud instances. This issue is fixed in version 1.121.3. Administrators can reduce exposure by disabling the Git node and limiting access for untrusted users, but upgrading to the latest version is recommended.

## Affected packages

- npm `n8n` >= 0.123.0, < 1.121.3 → fixed: 1.121.3

## Affected products (CVE record)

- n8n-io n8n: < 1.121.3

## Severity

- GitHub_M CVSS 3.1: 10 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`
- GitHub CVSS 3.1: 9.9 `CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H`

## Exploitation

- CISA KEV: not listed (no confirmed in-the-wild exploitation known to CISA).
- CISA SSVC assessment: exploitation none , automatable no , technical impact total .
- FIRST EPSS (model of 2026-10-21): 5.45% probability of exploitation activity in the next 30 days; percentile 93.

## Sources

- [GitHub Advisory GHSA-v364-rw7m-3263](https://github.com/advisories/GHSA-v364-rw7m-3263)
- [CVE.org record CVE-2026-21877](https://www.cve.org/CVERecord?id=CVE-2026-21877)
- [NVD entry CVE-2026-21877](https://nvd.nist.gov/vuln/detail/CVE-2026-21877)
- [github.com](https://github.com/n8n-io/n8n/security/advisories/GHSA-v364-rw7m-3263)
- [github.com](https://github.com/n8n-io/n8n/commit/f4b009d00d1f4ba9359b8e8f1c071e3d910a55f6)

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Source page: https://erroneo.us/security/cve/CVE-2026-21877/ · Security Digest: https://erroneo.us/security/ · More: https://erroneo.us/llms.txt