CVE-2026-21877 | n8n is vulnerable to Remote Code Execution via Arbitrary File Write

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.

Published: 2026-01-08 Last update: 2026-01-20 Assigner: [email protected] Source: [email protected]

Conclusion & alert: CVE-2026-21877 is rated High Risk (72/100): CVSS Critical severity, with high exploitation likelihood (EPSS 5.90%, 91th percentile). Core evidence: EPSS ranks this CVE among the most likely to be exploited in the near term. Mandatory action: High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2026-21877

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-05 5.26% 5.90% +0.64%
2 2026-06-04 10.73% 5.26% -5.48%
3 2026-05-18 10.73%

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2026-21877

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.9 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:C)
Breaking this can reach past the original component and bite other resources—bigger blast radius.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
3.1 6.0 [email protected]

Weakness enumeration for CVE-2026-21877

GitHub Security Advisory for CVE-2026-21877

GHSA-v364-rw7m-3263 · Severity: critical · Ecosystem: npm — n8n Vulnerable to RCE via Arbitrary File Write

Affected software / configurations for CVE-2026-21877

Vendor Product Version Raw CPE
n8n n8n >= 0.123.0, < 1.121.3 cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:*

References for CVE-2026-21877

cvelogic Threat Intelligence