Unpacking the n8n Identity Impersonation Vulnerability
n8n, the popular open-source platform for workflow automation, recently addressed a security vulnerability that could have allowed unauthorized users to impersonate others. This issue arises in n8n instances configured with multiple trusted identity providers for logging in. The core problem was an incomplete identity verification process: the system would only check a user’s identifier (known as the “sub” claim in a JWT token) and overlook the token’s issuer (the “iss” claim).
This oversight created a loophole. An attacker with a valid token from one trusted source could authenticate as a different user if their token’s “sub” claim matched a legitimate user’s “sub” claim from another trusted issuer. Essentially, the system trusted the “who” without verifying the “from where,” opening the door for unauthorized access and identity impersonation within the platform.
CVE Details
- Product: n8n
- Published: July 9, 2026
- Severity: Medium
- Status: Analyzed
Affected Products
The vulnerability impacts specific versions of the n8n workflow automation platform. Users running n8n are vulnerable if their instances are:
- Any version prior to 2.27.4
- Versions from 2.28.0 up to, but not including, 2.28.1
It’s crucial for all users operating these versions, especially those with multiple token-exchange issuers configured, to understand the risk this poses to their workflow security and user data.
Current Status
This vulnerability has been thoroughly analyzed, and official fixes have been released by the n8n development team. The issue is no longer a threat to instances running patched versions. This means that users have clear steps to take to secure their installations.
Severity Level
The Common Vulnerability Scoring System (CVSS) assigns this vulnerability a score of 6.8, classifying it as a Medium severity issue. A Medium severity indicates that while the vulnerability is not the most critical, it still presents a significant risk. Successful exploitation could lead to unauthorized access, allowing an attacker to impersonate legitimate users and potentially manipulate workflows or access sensitive data. Users should treat this rating seriously and apply patches promptly to mitigate potential risks.
Possible Solutions
To protect your n8n instance from this identity impersonation vulnerability, the most effective solution is to update your software to a patched version. The n8n development team has released the following versions that address this flaw:
- n8n version 2.27.4
- n8n version 2.28.1
If you are running any affected versions, it is highly recommended to upgrade to 2.27.4, 2.28.1, or any newer stable release as soon as possible. Regular updates are a fundamental cybersecurity practice to ensure your systems remain secure. For more general best practices on securing your automation workflows, consider reviewing articles on topics like Securing Workflow Automation Platforms.
References
- https://github.com/n8n-io/n8n/releases/tag/n8n%402.27.4
- https://github.com/n8n-io/n8n/releases/tag/n8n%402.28.1
- https://github.com/n8n-io/n8n/security/advisories/GHSA-mq3m-f8x3-579w
