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Luu, T.J.

GHSA-89gh-3pgc-v5h2: n8n: Custom Header Credential Values Leaked in Plaintext into LLM Node Execution Data

mediumvulnerabilityLLM-Specific

security

Source: GitHub Advisory DatabaseJuly 22, 2026CVE-2026-65589

Summary

n8n, a workflow automation tool, had a security flaw where custom HTTP headers (additional data sent with web requests) in LLM node credentials were hidden in the user interface but were actually saved in plaintext into execution data (the record of what happened when a workflow ran). This meant any authenticated user who could view that execution data could see API keys and other secrets stored in those headers. Since execution data can be saved to a database and exported, these secrets could remain exposed long after the workflow finished running.

Solution / Mitigation

The issue has been fixed in n8n versions 1.123.64, 2.29.8, and 2.30.1. Users should upgrade to one of these versions or later to remediate the vulnerability. If upgrading is not immediately possible, administrators can: restrict access to execution data to fully trusted users only; avoid configuring custom headers in LLM node credentials and use alternative authentication mechanisms instead; and rotate any API keys or secrets that may have been stored as custom header values in affected credentials. The source notes these workarounds do not fully remediate the risk and should only be used as short-term measures.