CVE-2026-59206: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in n8n-io n8n
n8n, an open source workflow automation platform, contains a prototype pollution vulnerability (CWE-1321) in versions prior to 1.123.61, 2.27.4, and 2.28.1. An authenticated user with the default workflow:create permission can craft workflows that pollute Object.prototype via the workflow API. This pollution can cause unauthenticated requests to be treated as privileged users, exposing user and project listing endpoints. The issue is fixed in versions 1.123.61, 2.27.4, and 2.28.1.
AI Analysis
Technical Summary
CVE-2026-59206 is a prototype pollution vulnerability in n8n that allows an authenticated user with workflow:create permission to modify Object.prototype through crafted workflows saved, updated, or imported via the workflow API. This improper control of object prototype attributes enables privilege escalation by causing unauthenticated requests to be treated as privileged, thereby exposing sensitive user and project listing endpoints. The vulnerability affects versions prior to 1.123.61, 2.27.4, and 2.28.1, where it has been fixed.
Potential Impact
The vulnerability allows an authenticated user with limited permissions to escalate privileges by polluting Object.prototype, leading to unauthorized access to user and project listing endpoints. This can result in exposure of sensitive information to unauthenticated users. The CVSS 4.0 score is 7.1 (high severity), reflecting network attack vector, low attack complexity, no user interaction, and significant impact on confidentiality and integrity.
Mitigation Recommendations
This vulnerability is fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to these or later versions to remediate the issue. No vendor advisory content contradicts this; therefore, upgrading is the recommended mitigation.
CVE-2026-59206: CWE-1321: Improperly Controlled Modification of Object Prototype Attributes ('Prototype Pollution') in n8n-io n8n
Description
n8n, an open source workflow automation platform, contains a prototype pollution vulnerability (CWE-1321) in versions prior to 1.123.61, 2.27.4, and 2.28.1. An authenticated user with the default workflow:create permission can craft workflows that pollute Object.prototype via the workflow API. This pollution can cause unauthenticated requests to be treated as privileged users, exposing user and project listing endpoints. The issue is fixed in versions 1.123.61, 2.27.4, and 2.28.1.
CVSS v4.0
Score 7.1high
Affected software
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-59206 is a prototype pollution vulnerability in n8n that allows an authenticated user with workflow:create permission to modify Object.prototype through crafted workflows saved, updated, or imported via the workflow API. This improper control of object prototype attributes enables privilege escalation by causing unauthenticated requests to be treated as privileged, thereby exposing sensitive user and project listing endpoints. The vulnerability affects versions prior to 1.123.61, 2.27.4, and 2.28.1, where it has been fixed.
Potential Impact
The vulnerability allows an authenticated user with limited permissions to escalate privileges by polluting Object.prototype, leading to unauthorized access to user and project listing endpoints. This can result in exposure of sensitive information to unauthenticated users. The CVSS 4.0 score is 7.1 (high severity), reflecting network attack vector, low attack complexity, no user interaction, and significant impact on confidentiality and integrity.
Mitigation Recommendations
This vulnerability is fixed in n8n versions 1.123.61, 2.27.4, and 2.28.1. Users should upgrade to these or later versions to remediate the issue. No vendor advisory content contradicts this; therefore, upgrading is the recommended mitigation.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- GitHub_M
- Date Reserved
- 2026-07-02T21:05:02.924Z
- Cvss Version
- 4.0
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4fbf4868715ace439fdd9d
Added to database: 07/09/2026, 15:33:28 UTC
Last enriched: 07/22/2026, 23:29:15 UTC
Last updated: 08/23/2026, 10:52:10 UTC
Views: 124
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