n8n: Authorization Bypass Through User-Controlled Key
CVE-2026-33724 is a high-severity authorization bypass through user-controlled key vulnerability in n8n, with a CVSS 3.1 base score of 7.4 out of 10. It can be exploited remotely over the network by an unauthenticated attacker, without any action from a user. Affected n8n versions: < 2.5.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.3% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of n8n you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on github.com for workarounds and exact fixed builds.
- Until you can update, restrict network access to the affected service so it is not reachable from untrusted networks.
Affected products and versions
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- NetworkCan be exploited remotely over a network, including the internet.
- Attack complexity
- HighSuccess depends on conditions outside the attacker's control.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- NoneAvailability is not affected.
Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 6.3 | Medium | CNA (github.com) |
| CVSS 3.1 | 7.4 | High | NVD |
Official description
n8n is an open source workflow automation platform. Prior to version 2.5.0, when the Source Control feature is configured to use SSH, the SSH command used for git operations explicitly disabled host key verification. A network attacker positioned between the n8n instance and the remote Git server could intercept the connection and present a fraudulent host key, potentially injecting malicious content into workflows or intercepting repository data. This issue only affects instances where the Source Control feature has been explicitly enabled and configured to use SSH (non-default). The issue has been fixed in n8n version 2.5.0. Users should upgrade to this version or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Disable the Source Control feature if it is not actively required, and/or restrict network access to ensure the n8n instance communicates with the Git server only over trusted, controlled network paths. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Authorization Bypass Through User-Controlled Key
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
How developers prevent this class of flaw
- For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
- Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
More Authorization Bypass Through User-Controlled Key vulnerabilities (CWE-639)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: partial).
- Record last changed materially (score, affected products, status or references).
References
Advisories
Other vulnerabilities in n8n
- 7.5 High severity
- 7.7 High severity
- 8.2 High severity
- 8.8 High severity
- 7.5 High severity
- 7.1 High severity
Recent Authorization Bypass Through User-Controlled Key vulnerabilities
- 9.8 Critical severity
- 8.6 High severity
- 9.8 Critical severity
- 8.1 High severity
- 9.1 Critical severity
- 8.8 High severity
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