Which versions of PostgreSQL are affected by CVE-2026-33663?

Authenticated n8n users can bypass authorization controls to steal plaintext credentials configured by other team members, creating a direct threat to downstream system compromises and data breaches.. A patch is available.

Is there a public PoC exploit available for CVE-2026-33663?

Yes, a public proof-of-concept exploit is available for CVE-2026-33663. Prioritise patching immediately. EPSS: 0.0%.

How to fix or mitigate CVE-2026-33663?

Within 24 hours: Audit n8n credential access logs and identify all HTTP-type credentials (httpBasicAuth, httpHeaderAuth, httpQueryAuth) currently stored; notify credential owners of potential exposure. Within 7 days: Implement network segmentation to restrict n8n access to essential users only, rotate all exposed HTTP-type credentials in downstream systems, and evaluate migration to n8n Enterprise (if credential isolation is available) or alternative platforms. Within 30 days: Deploy identity-based access controls limiting member-level users to their own credentials, implement comprehensive credential rotation for all integrations, and establish a credential governance policy prohibiting shared HTTP authentication.

PostgreSQL CVE-2026-33663

Q: What is the CVSS score of CVE-2026-33663?

CVE-2026-33663 has a CVSS 4.0 base score of 8.5 (High). CVSS vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/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. EPSS exploitation probability: 0.0%.

EUVD-2026-15943 HIGH

Authorization Bypass Through User-Controlled Key (CWE-639)

2026-03-25 GitHub_M

GHSA-m63j-689w-3j35

Authentication Bypass PostgreSQL

8.5

CVSS 4.0 · GitHub Advisory

Severity by source

GitHub Advisory PRIMARY

8.5 HIGH

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/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

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

CVSS VectorGitHub Advisory

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:H/SI:H/SA:H/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

Lifecycle Timeline

Patch released

Mar 31, 2026 - 21:13 nvd

Patch available

PoC Detected

Mar 31, 2026 - 16:39 vuln.today

Public exploit code

EUVD ID Assigned

Mar 25, 2026 - 17:47 euvd

EUVD-2026-15943

Analysis Generated

Mar 25, 2026 - 17:47 vuln.today

CVE Published

Mar 25, 2026 - 17:11 nvd

HIGH 8.5

DescriptionGitHub Advisory

n8n is an open source workflow automation platform. Prior to versions 2.14.1, 2.13.3, and 1.123.26, an authenticated user with the global:member role could exploit chained authorization flaws in n8n's credential pipeline to steal plaintext secrets from generic HTTP credentials (httpBasicAuth, httpHeaderAuth, httpQueryAuth) belonging to other users on the same instance. The attack abuses a name-based credential resolution path that does not enforce ownership or project scope, combined with a bypass in the credentials permission checker that causes generic HTTP credential types to be skipped during pre-execution validation. Together, these flaws allow a member-role user to resolve another user's credential ID and execute a workflow that decrypts and uses that credential without authorization. Native integration credential types (e.g. slackApi, openAiApi, postgres) are not affected by this issue. This vulnerability affects Community Edition only. Enterprise Edition has additional permission gates on workflow creation and execution that independently block this attack chain. The issue has been fixed in n8n versions 1.123.26, 2.13.3, and 2.14.1. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Restrict instance access to fully trusted users only, and/or audit credentials stored on the instance and rotate any generic HTTP credentials (httpBasicAuth, httpHeaderAuth, httpQueryAuth) that may have been exposed. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

AnalysisAI

n8n workflow automation platform Community Edition contains an authorization bypass vulnerability allowing authenticated users with member-level privileges to steal plaintext credentials from other users. The flaw chains name-based credential resolution that doesn't enforce ownership with a permissions bypass affecting generic HTTP credential types (httpBasicAuth, httpHeaderAuth, httpQueryAuth). Attackers can decrypt and exfiltrate credentials without authorization, though native integration credentials remain unaffected.

Technical ContextAI

The vulnerability affects n8n (CPE cpe:2.3:a:n8n-io:n8n), an open-source workflow automation platform built on Node.js. The root cause is CWE-639 (Authorization Bypass Through User-Controlled Key), where the credential resolution pipeline uses name-based lookups without validating ownership or project scope. The flaw is compounded by a second authorization weakness where the credential permission checker skips validation for generic HTTP authentication types during workflow execution. This allows an attacker to reference another user's credential by ID and bypass the intended access controls. The vulnerability specifically targets the credential decryption and usage pipeline, exposing the plaintext secrets during workflow execution. Enterprise Edition includes additional permission gates on workflow creation and execution that prevent exploitation of this chain.

RemediationAI

Upgrade n8n Community Edition to version 1.123.26, 2.13.3, 2.14.1, or later depending on your version branch to fully remediate the vulnerability (see vendor advisory at https://github.com/n8n-io/n8n/security/advisories/GHSA-m63j-689w-3j35). If immediate patching is not feasible, implement temporary mitigations including restricting instance access to fully trusted users only, conducting an audit of all stored credentials with focus on generic HTTP authentication types (httpBasicAuth, httpHeaderAuth, httpQueryAuth), and rotating any potentially exposed credentials. These workarounds provide only partial risk reduction and should be treated as short-term measures until proper patching can be completed. Consider migrating to native integration credential types where possible as they are not affected by this vulnerability.