n8n: Improper Control of Generation of Code
CVE-2026-77077 is a high-severity improper control of generation of code vulnerability in n8n, with a CVSS 3.1 base score of 7.6 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 1.123.69, 2.34.1, 2.33.4 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 0.56% 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 1.123.69 or 2.34.1 or 2.33.4, 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 | before 1.123.69; 2.34.0 up to, but not including, 2.34.1; 2.0.0 up to, but not including, 2.33.4 | 1.123.69, 2.34.1, 2.33.4 |
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
- LowLimited modification of data is possible.
- Availability
- LowPerformance or availability is reduced.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L. Scored by NVD.
| Scoring system | Score | Severity | Scored by |
|---|---|---|---|
| CVSS 4.0 | 7.2 | High | CNA (vulncheck.com) |
| CVSS 3.1 | 7.6 | High | NVD |
Official description
n8n versions before 1.123.69, 2.33.4, and 2.34.1 contain a JavaScript task runner VM sandbox escape. The runner's prototype-freezing routine covers globalThis functions but not internal module constructors such as EventEmitter, allowing an authenticated user with Code node access to exploit prototype pollution to execute arbitrary commands within the runner container. Because the polluted prototype is a process-wide object, the corruption persists across other tenants' Code node executions on the same shared runner. On v1.x instances without task runners enabled, Code node JavaScript runs directly in the main n8n process, where the impact could be higher.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Improper Control of Generation of Code
The product constructs all or part of a code segment using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the syntax or behavior of the intended code segment.
How developers prevent this class of flaw
- Refactor your program so that you do not have to dynamically generate code.
- Run your code in a jail or similar sandbox environment that enforces strict boundaries between the process and the operating system. This may effectively restrict which code can be executed by your product. Examples include the Unix chroot jail and AppArmor. In general, managed code may provide some protection. This may not be a feasible solution, and it only limits the impact to the operating system; the rest of your application may still be subject to compromise. Be careful to avoid CWE-243 and other weaknesses related to jails.
- Use dynamic tools and techniques that interact with the product using large test suites with many diverse inputs, such as fuzz testing (fuzzing), robustness testing, and fault injection. The product's operation may slow down, but it should not become unstable, crash, or generate incorrect results.
More Improper Control of Generation of Code vulnerabilities (CWE-94)
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
Third-party and government 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 Improper Control of Generation of Code vulnerabilities
- 9.8 Critical severity
- 7.8 High severity
- 7.8 High severity
- 7.3 High severity
- 8.8 High severity
- 8.8 High severity
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