n8n: Prototype Pollution via Dot-Notation Field Names Leads To Instance-Wide Denial of Service

## Impact The Edit Fields (Set) node assigned output fields through a dot-notation path setter without restricting the field name, so an authenticated user could name a field after an inherited built-in method path and corrupt a shared global in the main Node.js process. Because that global was used on the request-authentication path, the instance then failed every authenticated request, causing a instance-wide denial of service for all users until the process was restarted. ## Patches The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability. ## Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n instance access to fully trusted users only. - Disable or restrict workflow creation and execution permissions for untrusted users. - Monitor for unexpected process-wide HTTP 500 errors and restart the process promptly if they occur. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Source published

22 Jul 2026 22:12:33 UTC

Source modified

12 Aug 2026 04:26:16 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

Original source record · Cite this exact observation · Complete original publisher JSON

This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

Publisher rating · HIGH