n8n: Prototype Pollution enables confused-deputy execution via public webhooks

## Impact A prototype pollution vulnerability allowed a crafted public webhook payload to inject attacker-controlled fields into workflow data during internal object copying. These fields could be surfaced and consumed as normal values by downstream built-in nodes. Where a workflow combines a public webhook with action nodes that consume the resulting fields, an attacker could cause the workflow to act as a confused deputy — targeting unintended records or issuing outbound requests using the workflow owner's configured credentials. ## Patches The issue has been fixed in n8n versions 2.25.7, and 2.26.2. 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: - Avoid exposing public (unauthenticated) webhook workflows that pass incoming data through transform nodes into action nodes with sensitive credentials or database operations. - Limit workflow creation and editing permissions to fully trusted users only. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Source published

16 Jun 2026 19:00:41 UTC

Source modified

20 Jul 2026 14:00:27 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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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_V3 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:L/I:L/A:N

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

Publisher rating · MODERATE