CVE-2026-72769 n8n-io CVE debrief

Who should care

Defenders responsible for the security of n8n instances, particularly those using the VM expression engine, should be aware of this vulnerability. This includes administrators and security teams managing self-hosted or cloud-based n8n deployments. They should assess their exposure, verify the version of n8n in use, and apply patches or mitigations as necessary to prevent exploitation.

Why it matters

CVE-2026-72769 is a medium-severity vulnerability in n8n's VM expression engine that allows authenticated users to cause a denial of service. Defenders should verify n8n versions, restrict user permissions, and monitor for suspicious activity to mitigate potential impacts on workflow automation and business operations.

• Potential denial of service due to prototype pollution and sandbox escape
• Need for verification of n8n version and application of patches
• Monitoring for suspicious activity related to workflow expressions
• Possible impact on workflow automation and business operations

Technical summary

The vulnerability exists in the VM expression engine of n8n, allowing an authenticated user to create or edit a workflow expression and exploit the engine's array-element access to obtain a reference to a host built-in object. This can lead to prototype pollution in the main n8n process, enabling a sandbox escape and resulting in a denial of service. The vulnerability affects n8n versions before 1.123.67, 2.31.5, and 2.32.1.

Defensive priority

Defenders should prioritize verifying the version of n8n in use and applying the necessary patches to prevent exploitation. This involves reviewing the current version of n8n, identifying if it falls within the vulnerable range (before 1.123.67, 2.31.5, or 2.32.1), and updating to a secure version. Additionally, defenders should monitor for any suspicious activity that could indicate attempted exploitation.

Recommended defensive actions

• Verify the current version of n8n and update to a secure version if necessary
• Monitor for suspicious activity that could indicate attempted exploitation
• Review and restrict user permissions for creating or editing workflow expressions
• Confirm whether affected n8n deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details about the vulnerability, including its description, CVSS score, and affected versions. However, the record of exploitation attempts or successful breaches is not provided, limiting the understanding of the vulnerability's impact.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.