n8n EUVD-2026-63265

Exploitation requires an authenticated n8n user account with at least read access to workflow execution records for the targeted workflow - PR:L confirms authentication is mandatory. The vulnerable code path triggers only when a GraphQL node is configured to use n8n's built-in credential system (credentials stored in the n8n vault, not inline values), and only when the HTTP request fails at the transport/connection layer rather than returning an application-level GraphQL error. A connection failure must occur or be engineered during execution. Limiting factors: unauthenticated exploitation is not possible; deployments where execution-read access is restricted to fully trusted administrators substantially reduce exposure; workflows that do not use the GraphQL node or that use inline/environment-sourced credentials rather than the n8n credential store are not affected; and the specific failure mode requires a connection-level (not application-level) error, which may not occur without attacker influence over network reachability.

The CVSS 4.0 vector (AV:N/AC:L/AT:N/PR:L/UI:N/VC:H) signals a network-reachable, low-complexity attack requiring only a standard authenticated account, with high confidentiality impact and no attack-requirement preconditions beyond authentication. Exploitation status is no public exploit identified at time of analysis - the vulnerability is absent from CISA KEV and no POC code is referenced in available intelligence. Despite the absence of confirmed exploitation, the real-world risk is disproportionately high relative to a typical 7.1: credential secrets (API keys, tokens, passwords) are exposed directly in plaintext in execution records, enabling lateral movement to any external service integrated through the affected GraphQL node. In multi-user or team deployments, the blast radius extends to all credentials accessible via GraphQL nodes across all workflows any low-privileged user can read. EPSS data was not provided in the supplied intelligence sources, so probabilistic exploitation likelihood cannot be quantified; however, the trivial exploitation mechanics and high-value payload argue for treating this at the upper end of the 4.0 score band. No conflicting signals were identified between the CVSS vector and the vulnerability description.

An attacker with a low-privileged n8n account identifies a workflow containing a GraphQL node configured with a stored credential. They trigger a connection-level failure - either by temporarily making the target GraphQL endpoint unreachable or by waiting for an organic failure - causing the workflow execution to fail and persist the raw HTTP error (including decrypted Authorization headers) to the execution log. The attacker then reads the execution record via the n8n web UI or API and extracts the plaintext credential, which can subsequently be used to access the external service the credential was meant to protect. No public exploit code has been identified at time of analysis.