What is the CVSS score of CVE-2026-21858?

CVE-2026-21858 has a CVSS 3.1 base score of 10.0 (Critical). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N. EPSS exploitation probability: 7.1%.

Which versions of Node.js are affected by CVE-2026-21858?

Organizations using n8n face critical risk from CVE-2026-21858, a input validation vulnerability rated CVSS 10.0.. A patch is available.

Is there a public PoC exploit available for CVE-2026-21858?

Yes, a public proof-of-concept exploit is available for CVE-2026-21858. Prioritise patching immediately. EPSS: 7.1%.

How to fix or mitigate CVE-2026-21858?

Within 24 hours: Identify all affected systems and apply vendor patches immediately. Monitor vendor channels for patch availability.

Node.js CVE-2026-21858

CRITICAL

Improper Input Validation (CWE-20)

2026-01-08 security-advisories@github.com

GHSA-v4pr-fm98-w9pg

Information Disclosure Path Traversal LFI Node.js N8n

10.0

CVSS 3.1 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

10.0 CRITICAL

AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

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

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

None

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

Analysis Generated

Mar 12, 2026 - 21:54 vuln.today

PoC Detected

Jan 16, 2026 - 19:31 vuln.today

Public exploit code

CVE Published

Jan 08, 2026 - 00:15 nvd

CRITICAL 10.0

DescriptionGitHub Advisory

n8n is an open source workflow automation platform. Versions starting with 1.65.0 and below 1.121.0 enable an attacker to access files on the underlying server through execution of certain form-based workflows. A vulnerable workflow could grant access to an unauthenticated remote attacker, resulting in exposure of sensitive information stored on the system and may enable further compromise depending on deployment configuration and workflow usage. This issue is fixed in version 1.121.0.

AnalysisAI

n8n workflow automation (1.65.0 to 1.121.0) allows unauthenticated file access through form-based workflows. A critical CVSS 10.0 vulnerability enabling remote attackers to read sensitive files from the server, with potential for further compromise. PoC available.

Technical ContextAI

Form-based workflows in n8n can be crafted to access local files on the server (CWE-20). Since these workflows can be triggered by unauthenticated users, any sensitive file (environment variables, database credentials, private keys) is accessible. The scope change reflects that n8n servers typically have access to connected service credentials.

RemediationAI

Update to n8n 1.121.1 or later. Never expose n8n to the internet without authentication. Rotate all credentials stored in n8n if exposure is suspected.