Skip to main content

n8n EUVDEUVD-2026-63262

| CVE-2026-77073 MEDIUM
Authorization Bypass Through User-Controlled Key (CWE-639)
2026-08-20 VulnCheck GHSA-hf5p-745p-2j3h
Authentication Bypass N8n
5.3
CVSS 4.0 · Vendor: VulnCheck
Share

Severity by source

Vendor (VulnCheck) PRIMARY
5.3 MEDIUM
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
vuln.today AI
5.0 MEDIUM

Network attack by low-privilege MCP key holder; scope change applies as impact crosses project boundaries; no confidentiality loss, only unauthorized integrity write.

3.1 AV:N/AC:L/PR:L/UI:N/S:C/C:N/I:L/A:N
4.0 AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N

Primary rating from Vendor (VulnCheck).

CVSS VectorVendor: VulnCheck

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:L/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
X

Lifecycle Timeline

2
Patch available
Aug 20, 2026 - 12:16 EUVD
Analysis Generated
Aug 20, 2026 - 12:14 vuln.today

DescriptionCVE.org

n8n versions before 2.34.1 contain a credential validation bypass in the MCP create_workflow_from_code tool when authentication type is set to an expression. Attackers with a valid MCP Bearer API key and knowledge of a target credential ID can persist unauthorized cross-project credential references on workflows in different projects.

AnalysisAI

Cross-project credential reference injection in n8n before 2.34.1 allows low-privileged attackers holding a valid MCP Bearer API key to bypass authorization controls in the create_workflow_from_code MCP tool and embed references to credentials belonging to other projects into workflows they should not control. The bypass is conditional on the credential authentication type being set to 'expression', at which point n8n fails to enforce project-scoped authorization on credential objects. …

Unlock full vulnerability intelligence

  • Risk assessment & exploitation conditions
  • Attack chain visualization
  • Remediation with exact patch versions
  • Threat intelligence from 22 sources
  • Personal watchlist & email alerts
Continue with Google Continue with GitHub

Free forever · No credit card required

Attack ChainAIDerived

Hypothetical attack flow derived from CVE metadata

Access
Obtain valid MCP Bearer API key
Delivery
Enumerate target credential ID across project boundary
Exploit
Craft create_workflow_from_code request with expression auth type
Execution
Bypass credential project-scope validation
Persist
Persist unauthorized credential reference in victim project workflow
Impact
Trigger workflow execution using stolen credential reference
Sign in to reveal

Vulnerability AssessmentAI

Exploitation Exploitation requires: (1) a valid MCP Bearer API key for the n8n instance, establishing a low-privilege authenticated foothold; (2) knowledge or enumeration of a target credential ID belonging to a different project; (3) the target credential must be configured with authentication type set to 'expression' - this is the specific configuration state that triggers the validation bypass; and (4) the n8n MCP server interface must be reachable over the network. … Additional conditions and limiting factors are described in the full assessment.
Risk Assessment The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N) with scores across VC:N/VI:L/VA:N/SC:N/SI:L/SA:N accurately captures the impact: low-complexity network exploitation by a low-privilege attacker, with integrity effects limited to unauthorized reference persistence rather than direct credential exfiltration. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in.
Exploit Scenario An attacker operating in a shared n8n instance obtains a valid MCP Bearer API key - either legitimately through a low-privilege account or via a compromised key. They enumerate or guess a credential ID belonging to a different project, then call the create_workflow_from_code MCP tool with a workflow definition that references that credential under an 'expression' authentication type. …
Remediation Upgrade to n8n version 2.34.1 or later, which resolves the credential validation bypass per the vendor advisory at https://github.com/n8n-io/n8n/security/advisories/GHSA-vfrj-582q-mvcp. … Detailed patch versions, workarounds, and compensating controls in full report.
Sign in to read full assessment

Threat intelligence, references, and detailed analysis are available after sign-in.

More in N8n

View all
CVE-2026-21877 CRITICAL POC
9.9 Jan 08

n8n workflow automation (through 1.121.2) allows authenticated users to execute arbitrary code via the n8n service, with
CVE-2026-21858 CRITICAL POC
10.0 Jan 08

n8n workflow automation (1.65.0 to 1.121.0) allows unauthenticated file access through form-based workflows. A critical

CVE-2026-1470 CRITICAL POC
9.9 Jan 27

n8n has a fifth critical RCE vulnerability (CVSS 9.9) in the Expression evaluator, enabling code execution through craft
CVE-2026-33660 CRITICAL POC
9.4 Mar 25

An authenticated user with workflow creation or modification privileges in n8n workflow automation platform can exploit

CVE-2026-33665 HIGH POC
8.8 Mar 25

Authenticated n8n users can hijack administrator accounts when LDAP authentication is enabled by manipulating their LDAP
CVE-2023-27563 HIGH POC
8.8 May 10

The n8n package 0.218.0 for Node.js allows Escalation of Privileges. Rated high severity (CVSS 8.8), this vulnerability

CVE-2026-0863 HIGH POC
8.5 Jan 18

Authenticated users can exploit string formatting and exception handling in n8n's Python task executor to escape sandbox
CVE-2023-27564 HIGH POC
7.5 May 10

The n8n package 0.218.0 for Node.js allows Information Disclosure. Rated high severity (CVSS 7.5), this vulnerability is
CVE-2023-27562 MEDIUM POC
6.5 May 10

The n8n package 0.218.0 for Node.js allows Directory Traversal. Rated medium severity (CVSS 6.5), this vulnerability is

CVE-2026-33724 MEDIUM POC
6.3 Mar 25

n8n versions prior to 2.5.0 contain a critical SSH host key verification bypass in the Source Control feature that allow
CVE-2026-33720 MEDIUM POC
6.3 Mar 25

This vulnerability in n8n (an open-source workflow automation platform) is an authentication bypass in the OAuth callbac
CVE-2026-27495 CRITICAL
9.9 Feb 25

Code injection in n8n workflow automation before 2.10.1/2.9.3/1.123.22 allows authenticated users to execute arbitrary c

Same weakness CWE-639 – Authorization Bypass Through User-Controlled Key

View all
CVE-2024-50483 CRITICAL
9.8
CVE-2026-55255 HIGH POC
8.4
CVE-2025-3605 CRITICAL POC
9.8
CVE-2022-3805 HIGH POC
8.6
CVE-2025-5947 CRITICAL POC
9.8
CVE-2020-36923 CRITICAL POC
9.8
CVE-2025-14998 CRITICAL POC
9.8
CVE-2023-3048 CRITICAL POC
9.8

Same technique Authentication Bypass

View all
CVE-2023-22515 CRITICAL POC
9.8
CVE-2012-4681 CRITICAL POC
9.8
CVE-2013-2465 CRITICAL POC
9.8
CVE-2011-3544 CRITICAL POC
9.8
CVE-2022-40684 CRITICAL POC
9.8
CVE-2025-61882 CRITICAL POC
9.8
CVE-2024-0012 CRITICAL POC
9.3
CVE-2023-46805 HIGH POC
8.2

Share

EUVD-2026-63262 vulnerability details – vuln.today
Back

This site uses cookies essential for authentication and security. No tracking or analytics cookies are used. Privacy Policy