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10.0
CRITICAL CVSS 3.1
CVE-2026-21858
n8n Vulnerable to Unauthenticated File Access via Improper Webhook Request Handling
Description

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.

INFO

Published Date :

Jan. 8, 2026, 12:15 a.m.

Last Modified :

Jan. 16, 2026, 7:31 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
Affected Products

The following products are affected by CVE-2026-21858 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 N8n n8n
: Total Affected Vendor : 1 | Products : 1
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 3.1 CRITICAL [email protected]
Solution
Update n8n to version 1.121.0 or later to fix file access vulnerabilities.
  • Update n8n to version 1.121.0.
  • Apply security patches for affected versions.
  • Review and secure workflow configurations.
Public PoC/Exploit Available at Github

CVE-2026-21858 has a 25 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2026-21858.

URL Resource
https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg Vendor Advisory
https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858 Exploit Third Party Advisory
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2026-21858 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2026-21858 weaknesses.

CAPEC-3: Using Leading 'Ghost' Character Sequences to Bypass Input Filters Using Leading 'Ghost' Character Sequences to Bypass Input Filters CAPEC-7: Blind SQL Injection Blind SQL Injection CAPEC-8: Buffer Overflow in an API Call Buffer Overflow in an API Call CAPEC-9: Buffer Overflow in Local Command-Line Utilities Buffer Overflow in Local Command-Line Utilities CAPEC-10: Buffer Overflow via Environment Variables Buffer Overflow via Environment Variables CAPEC-13: Subverting Environment Variable Values Subverting Environment Variable Values CAPEC-14: Client-side Injection-induced Buffer Overflow Client-side Injection-induced Buffer Overflow CAPEC-22: Exploiting Trust in Client Exploiting Trust in Client CAPEC-23: File Content Injection File Content Injection CAPEC-24: Filter Failure through Buffer Overflow Filter Failure through Buffer Overflow CAPEC-28: Fuzzing Fuzzing CAPEC-31: Accessing/Intercepting/Modifying HTTP Cookies Accessing/Intercepting/Modifying HTTP Cookies CAPEC-42: MIME Conversion MIME Conversion CAPEC-43: Exploiting Multiple Input Interpretation Layers Exploiting Multiple Input Interpretation Layers CAPEC-45: Buffer Overflow via Symbolic Links Buffer Overflow via Symbolic Links CAPEC-46: Overflow Variables and Tags Overflow Variables and Tags CAPEC-47: Buffer Overflow via Parameter Expansion Buffer Overflow via Parameter Expansion CAPEC-52: Embedding NULL Bytes Embedding NULL Bytes CAPEC-53: Postfix, Null Terminate, and Backslash Postfix, Null Terminate, and Backslash CAPEC-63: Cross-Site Scripting (XSS) Cross-Site Scripting (XSS) CAPEC-64: Using Slashes and URL Encoding Combined to Bypass Validation Logic Using Slashes and URL Encoding Combined to Bypass Validation Logic CAPEC-67: String Format Overflow in syslog() String Format Overflow in syslog() CAPEC-71: Using Unicode Encoding to Bypass Validation Logic Using Unicode Encoding to Bypass Validation Logic CAPEC-72: URL Encoding URL Encoding CAPEC-73: User-Controlled Filename User-Controlled Filename CAPEC-78: Using Escaped Slashes in Alternate Encoding Using Escaped Slashes in Alternate Encoding CAPEC-79: Using Slashes in Alternate Encoding Using Slashes in Alternate Encoding CAPEC-80: Using UTF-8 Encoding to Bypass Validation Logic Using UTF-8 Encoding to Bypass Validation Logic CAPEC-81: Web Server Logs Tampering Web Server Logs Tampering CAPEC-83: XPath Injection XPath Injection CAPEC-85: AJAX Footprinting AJAX Footprinting CAPEC-88: OS Command Injection OS Command Injection CAPEC-101: Server Side Include (SSI) Injection Server Side Include (SSI) Injection CAPEC-104: Cross Zone Scripting Cross Zone Scripting CAPEC-108: Command Line Execution through SQL Injection Command Line Execution through SQL Injection CAPEC-109: Object Relational Mapping Injection Object Relational Mapping Injection CAPEC-110: SQL Injection through SOAP Parameter Tampering SQL Injection through SOAP Parameter Tampering CAPEC-120: Double Encoding Double Encoding CAPEC-135: Format String Injection Format String Injection CAPEC-136: LDAP Injection LDAP Injection CAPEC-153: Input Data Manipulation Input Data Manipulation CAPEC-182: Flash Injection Flash Injection CAPEC-209: XSS Using MIME Type Mismatch XSS Using MIME Type Mismatch CAPEC-230: Serialized Data with Nested Payloads Serialized Data with Nested Payloads CAPEC-231: Oversized Serialized Data Payloads Oversized Serialized Data Payloads CAPEC-250: XML Injection XML Injection CAPEC-261: Fuzzing for garnering other adjacent user/sensitive data Fuzzing for garnering other adjacent user/sensitive data CAPEC-267: Leverage Alternate Encoding Leverage Alternate Encoding CAPEC-473: Signature Spoof Signature Spoof CAPEC-588: DOM-Based XSS DOM-Based XSS CAPEC-664: Server Side Request Forgery Server Side Request Forgery

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
Alhakim88/CVE-2026-21858

Hack

Dockerfile Python Shell Perl

Updated: 5 hours, 14 minutes ago
0 stars 0 fork 0 watcher
Born at : Jan. 30, 2026, 10:38 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
SimoesCTT/Vortex-DWM-ASLR-Killer

vortex_dwm.py (The ASLR-Defeat Core) ​This script targets the ALPC (Advanced Local Procedure Call) port used by the Desktop Window Manager. It utilizes the \alpha=0.0302 timing constant to intercept the memory section handle during a state-restoration cycle.

Python

Updated: 16 hours, 33 minutes ago
0 stars 0 fork 0 watcher
Born at : Jan. 30, 2026, 11:20 a.m. This repo has been linked 3 different CVEs too.
Profile Photo
NOTTIBOY137/RulesGuard

Security scanner for AI IDE configuration files (.cursorrules, .vscode/settings.json) - detects Unicode obfuscation + risky patterns

ai-security cursor cve devsecops python scanner security supply-chain-security vscode vulnerability-scanner

Python

Updated: 4 days, 23 hours ago
0 stars 0 fork 0 watcher
Born at : Jan. 24, 2026, 2:08 a.m. This repo has been linked 2 different CVEs too.
Profile Photo
master-crypto/recon-master

Ultimate Bug Bounty Reconnaissance Tool

Python Shell

Updated: 1 week, 1 day ago
0 stars 0 fork 0 watcher
Born at : Jan. 22, 2026, 11:03 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
MOGMUNI/mogmuni.github.io

🛡️ Exploit CVE-2026-21858 for unauthenticated RCE in n8n; includes proof of concept and mitigation details for critical vulnerabilities.

Updated: 1 week ago
0 stars 0 fork 0 watcher
Born at : Jan. 21, 2026, 3:01 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
SystemVll/CVE-2026-21858

Proof of Concept: CVE-2026-21858 is vulnerability on n8n where unauthenticated remote attackers can access sensitive files.

cve cve-2026-21858 exploit n8n n8n-exploits nuclei poc vuln

Python

Updated: 1 week ago
2 stars 0 fork 0 watcher
Born at : Jan. 20, 2026, 3:59 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
sec-dojo-com/CVE-2026-21858

None

Python

Updated: 1 week, 3 days ago
0 stars 0 fork 0 watcher
Born at : Jan. 20, 2026, 11:50 a.m. This repo has been linked 2 different CVEs too.
Profile Photo
sastraadiwiguna-purpleeliteteaming/SASTRA-ADI-WIGUNA-CVE-2026-21858-Holistic-Audit

SASTRA-ADI-WIGUNA-CVE-2026-21858-Holistic-Audit

Updated: 1 week, 5 days ago
0 stars 0 fork 0 watcher
Born at : Jan. 17, 2026, 4:57 a.m. This repo has been linked 1 different CVEs too.
Profile Photo
galois17/n8n-ni8mare-educational

None

Shell

Updated: 2 weeks, 1 day ago
0 stars 0 fork 0 watcher
Born at : Jan. 15, 2026, 9:14 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
cropnet/ni8mare-scanner

Comprehensive vulnerability detection tool for n8n workflow automation instances. Detects the critical CVE-2026-21858 vulnerability (CVSS 10.0) without performing any exploitation.

cve-2026-21858

Dockerfile Python

Updated: 2 weeks, 4 days ago
0 stars 0 fork 0 watcher
Born at : Jan. 12, 2026, 2:32 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
Ashwesker/Ashwesker-CVE-2026-21858

CVE-2026-21858

Updated: 2 weeks, 5 days ago
1 stars 0 fork 0 watcher
Born at : Jan. 7, 2026, 8:36 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
Chocapikk/CVE-2026-21858

n8n Ni8mare - Unauthenticated Arbitrary File Read to RCE Chain (CVSS 10.0)

exploit n8n poc rce security vulnerability cve-2026-21858 ni8mare

Dockerfile Python Shell

Updated: 2 weeks, 3 days ago
207 stars 43 fork 43 watcher
Born at : Jan. 7, 2026, 7:32 p.m. This repo has been linked 3 different CVEs too.
Profile Photo
eduardorossi84/CVE-2026-21858-POC

A maximum severity vulnerability dubbed "Ni8mare" allows remote, unauthenticated attackers to take control over locally deployed instances of the N8N workflow automation platform.

Updated: 3 weeks, 1 day ago
1 stars 0 fork 0 watcher
Born at : Jan. 7, 2026, 7:11 p.m. This repo has been linked 1 different CVEs too.
Profile Photo
hlsitechio/shellockolm

Security Detective for React, Next.js, Node.js & npm - CVE scanner, malware detector, secrets finder, SBOM generator. 60+ commands. Zero config.

cve cybersecurity devsecops nextjs python react security security-tools vulnerability-management vulnerability-scanner malware-detection npm supply-chain-security threat-detection model-context-protocol security-automation bug-bounty cli nodejs sbom

Python Shell

Updated: 2 days, 23 hours ago
2 stars 0 fork 0 watcher
Born at : Dec. 6, 2025, 11:29 p.m. This repo has been linked 28 different CVEs too.
Profile Photo
CPAtoCybersecurity/GRC_News_Assistant_3

GRC News Assistant 3.0

Updated: 1 week, 6 days ago
3 stars 0 fork 0 watcher
Born at : Nov. 22, 2025, 11:09 p.m. This repo has been linked 4 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-21858 vulnerability anywhere in the article.

  • BleepingComputer
New sandbox escape flaw exposes n8n instances to RCE attacks

Two vulnerabilities in the n8n workflow automation platform could allow attackers to fully compromise affected instances, access sensitive data, and execute arbitrary code on the underlying host. Iden ... Read more

Published Date: Jan 28, 2026 (2 days, 10 hours ago)
  • The Hacker News
Two High-Severity n8n Flaws Allow Authenticated Remote Code Execution

Cybersecurity researchers have disclosed two new security flaws in the n8n workflow automation platform, including a crucial vulnerability that could result in remote code execution. The weaknesses, d ... Read more

Published Date: Jan 28, 2026 (2 days, 15 hours ago)
  • Daily CyberSecurity
Sandbox Shattered: Critical n8n Flaw (CVSS 9.9) Allows Remote Code Execution

Security researcher Natan Nehorai of the JFrog Security Research Team has uncovered a critical Remote Code Execution (RCE) vulnerability in n8n, the popular fair-code workflow automation platform used ... Read more

Published Date: Jan 28, 2026 (2 days, 23 hours ago)
  • Schneier on Security
New Vulnerability in n8n

This isn’t good: We discovered a critical vulnerability (CVE-2026-21858, CVSS 10.0) in n8n that enables attackers to take over locally deployed instances, impacting an estimated 100,000 servers global ... Read more

Published Date: Jan 15, 2026 (2 weeks, 1 day ago)
  • The Cyber Express
What Is a DNS Attack? Understanding the Risks and Threats

In 2026, when websites, apps, and online services drive nearly every aspect of daily life, the Domain Name System (DNS) acts as the internet’s unsung hero. It serves as the bridge between humans and m ... Read more

Published Date: Jan 13, 2026 (2 weeks, 3 days ago)
  • CybersecurityNews
100,000+ n8n Instances Exposed to Internet Vulnerable to RCE Attacks

A critical vulnerability affecting the popular n8n workflow automation platform has put over 100,000 internet-exposed instances at severe risk. Security researchers from The Shadowserver Foundation di ... Read more

Published Date: Jan 13, 2026 (2 weeks, 3 days ago)
  • BleepingComputer
Max severity Ni8mare flaw impacts nearly 60,000 n8n instances

Nearly 60,000 n8n instances exposed online remain unpatched against a maximum-severity vulnerability dubbed "Ni8mare." n8n is an open-source workflow automation platform that allows users to connect d ... Read more

Published Date: Jan 12, 2026 (2 weeks, 4 days ago)
  • security.nl
Zestigduizend n8n-servers missen update voor zeer kritiek beveiligingslek

Zo'n zestigduizend servers waarop n8n draait, waaronder veertienhonderd in Nederland, missen een beveiligingsupdate voor een zeer kritieke kwetsbaarheid. Dat meldt The Shadowserver Foundation op basis ... Read more

Published Date: Jan 12, 2026 (2 weeks, 4 days ago)
  • TheCyberThrone
Critical Ni8mare RCE and Expression Injection Vulnerability

January 10, 2026n8n, the popular open-source workflow automation tool, faces multiple critical vulnerabilities disclosed in late 2025 and early 2026. These flaws enable unauthenticated remote code exe ... Read more

Published Date: Jan 10, 2026 (3 weeks ago)
  • SentinelOne
The Good, the Bad and the Ugly in Cybersecurity – Week 2

The Good | U.K. Government Resets Public-Sector Cybersecurity With £210M Action Plan The United Kingdom has unveiled a sweeping reset of its public-sector cybersecurity strategy, committing more than ... Read more

Published Date: Jan 09, 2026 (3 weeks ago)
  • SentinelOne
The Good, the Bad and the Ugly in Cybersecurity – Week 2

The Good | U.K. Government Resets Public-Sector Cybersecurity With £210M Action Plan The United Kingdom has unveiled a sweeping reset of its public-sector cybersecurity strategy, committing more than ... Read more

Published Date: Jan 09, 2026 (3 weeks ago)
  • security.nl
NCSC verwacht misbruik van kritieke Ni8mare-kwetsbaarheid in n8n

Het Nationaal Cyber Security Centrum (NCSC) verwacht dat aanvallers misbruik zullen gaan maken van een kritieke kwetsbaarheid in n8n, aangeduid als Ni8mare en CVE-2026-21858, waardoor ongeauthenticeer ... Read more

Published Date: Jan 08, 2026 (3 weeks, 1 day ago)
  • The Register
Maximum-severity n8n flaw lets randos run your automation server

A maximum-severity bug in the popular automation platform n8n has left an estimated 100,000 servers wide open to complete takeover, courtesy of a flaw so bad it doesn't even require logging in. The vu ... Read more

Published Date: Jan 08, 2026 (3 weeks, 1 day ago)
  • Daily CyberSecurity
CISA KEV Alert: HPE’s Maximum CVSS Score Flaw and a Zombie PowerPoint Bug

The Cybersecurity and Infrastructure Security Agency (CISA) has updated its Known Exploited Vulnerabilities (KEV) Catalog with two new entries that span nearly two decades of computing history. The la ... Read more

Published Date: Jan 08, 2026 (3 weeks, 1 day ago)
  • Daily CyberSecurity
Public Exploit Released: Critical n8n Flaw CVE-2026-21858 Exposes 100k Servers

The “central nervous system” of automation for thousands of companies has a critical weakness. A new report from Cyera reveals a devastating vulnerability in n8n, the popular workflow automation platf ... Read more

Published Date: Jan 08, 2026 (3 weeks, 2 days ago)
  • Daily CyberSecurity
“VM Isolation is Not Absolute”: Researchers Unmask Sophisticated ESXi “Maestro” Exploit

In a new report, the Huntress Tactical Response Team details a sophisticated intrusion discovered in December 2025 where threat actors successfully executed a “VM escape”—breaking out of a guest virtu ... Read more

Published Date: Jan 08, 2026 (3 weeks, 2 days ago)

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2026-21858 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Initial Analysis by [email protected]

    Jan. 16, 2026

    Action Type Old Value New Value
    Added CPE Configuration OR *cpe:2.3:a:n8n:n8n:*:*:*:*:*:node.js:*:* versions from (including) 1.65.0 up to (excluding) 1.121.0
    Added Reference Type GitHub, Inc.: https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg Types: Vendor Advisory
    Added Reference Type GitHub, Inc.: https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858 Types: Exploit, Third Party Advisory
  • CVE Modified by [email protected]

    Jan. 12, 2026

    Action Type Old Value New Value
    Added Reference https://www.cyera.com/research-labs/ni8mare-unauthenticated-remote-code-execution-in-n8n-cve-2026-21858
  • CVE Modified by [email protected]

    Jan. 08, 2026

    Action Type Old Value New Value
    Changed Description n8n is an open source workflow automation platform. Versions 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. 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.
  • New CVE Received by [email protected]

    Jan. 08, 2026

    Action Type Old Value New Value
    Added Description n8n is an open source workflow automation platform. Versions 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.
    Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:N
    Added CWE CWE-20
    Added Reference https://github.com/n8n-io/n8n/security/advisories/GHSA-v4pr-fm98-w9pg
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 10.0
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact