n8n: Improperly Controlled Modification of Object Prototype Attributes
CVE-2026-118649 is a high-severity improperly controlled modification of object prototype attributes vulnerability in n8n, with a CVSS 3.1 base score of 8.3 out of 10. It can be exploited remotely over the network by an attacker with a low-privileged account, without any action from a user. The record lists versions 2.44.1, 2.43.5 as the first without the flaw, so updating n8n to one of those releases or later removes the exposure. There is no confirmed exploitation so far. EPSS estimates a 0.27% 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
- Update n8n to 2.44.1 or 2.43.5, whichever matches your release line, or a later version.
- Read the advisory on github.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| n8n | n8n | 2.44.0 up to, but not including, 2.44.1; before 2.43.5 | 2.44.1, 2.43.5 |
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
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- LowA basic user account is enough.
- 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
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L. Scored by CNA (vulncheck.com).
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 8.7 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 8.3 | High | CNA (vulncheck.com) |
Official description
n8n before 2.43.5 and 2.44.x before 2.44.1 accepts a client-supplied workflow ID and caches each workflow's owner project in memory by that ID, so a crafted ID such as __proto__ makes the Data Table project check match every project. An authenticated member who can create and run workflows can list, read, modify, and delete Data Table rows in all projects of the instance.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improperly Controlled Modification of Object Prototype Attributes
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.
How developers prevent this class of flaw
- By freezing the object prototype first (for example, Object.freeze(Object.prototype)), modification of the prototype becomes impossible.
- By blocking modifications of attributes that resolve to object prototype, such as proto or prototype, this weakness can be mitigated.
- When handling untrusted objects, validating using a schema can be used.
More Improperly Controlled Modification of Object Prototype Attributes vulnerabilities (CWE-1321)
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
- Record last changed materially (score, affected products, status or references).
References
Other references
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 Improperly Controlled Modification of Object Prototype Attributes vulnerabilities
- 7.2 High severity
- 7.2 High severity
- 8.8 High severity
- 7.5 High severity
- 7.7 High severity
- 7.5 High severity
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