Summary
n8n: Custom Header Credential Values Leaked in Plaintext into LLM Node Execution Data
Workarounds
If upgrading is not immediately possible, administrators should consider the following temporary mitigations:
- Restrict access to execution data to fully trusted users only.
- Avoid configuring custom headers in LLM node credentials; use alternative authentication mechanisms where possible.
- Rotate any API keys or secrets that may have been stored as custom header values in affected credentials.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Impact
Custom HTTP headers configured in credentials for certain LLM sub-nodes (including OpenAI, Anthropic, and Lemonade) are masked in the n8n UI but are written in plaintext into execution data during workflow runs. Any authenticated user with access to the execution data for an affected workflow can read the header names and values, which typically contain API keys or other secrets.
Because execution data can be persisted to the database and exported, leaked values may remain accessible beyond the lifetime of a single execution.
This issue only affects instances where workflows use LLM sub-nodes with custom headers defined in their credentials.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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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.
Frequently Asked Questions
- What is CVE-2026-65589? CVE-2026-65589 is a medium-severity security vulnerability in n8n (npm), affecting versions < 1.123.64. It is fixed in 1.123.64, 2.30.1, 2.29.8.
- Which versions of n8n are affected by CVE-2026-65589? n8n (npm) versions < 1.123.64 is affected.
- Is there a fix for CVE-2026-65589? Yes. CVE-2026-65589 is fixed in 1.123.64, 2.30.1, 2.29.8. Upgrade to this version or later.
- Is CVE-2026-65589 exploitable, and should I be worried? Whether CVE-2026-65589 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2026-65589 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2026-65589?
- Upgrade
n8nto 1.123.64 or later - Upgrade
n8nto 2.30.1 or later - Upgrade
n8nto 2.29.8 or later
- Upgrade