CVE-2026-27496: n8n has In-Process Memory Disclosure in its Task Runner
Impact An authenticated user with permission to create or modify workflows could use the JavaScript Task Runner to allocate uninitialized memory buffers. Uninitialized buffers may contain residual data from the same Node.js process — including data from prior requests, tasks, secrets, or tokens — resulting in information disclosure of sensitive in-process data. - Task Runners must be enabled using N8NRUNNERSENABLED=true. - In external runner mode, the impact is limited to data within the external runner process.
Patches The issue has been fixed in n8n versions >= 1.123.22, >= 2.10.1 , and >= 2.9.3. Users should upgrade to this version or later to remediate the vulnerability.
Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Limit workflow creation and editing permissions to fully trusted users only. - Use external runner mode (N8NRUNNERSMODE=external) to isolate the runner process.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Other sources
n8n is an open source workflow automation platform. Prior to versions 1.123.22, 2.9.3, and 2.10.1, an authenticated user with permission to create or modify workflows could use the JavaScript Task Runner to allocate uninitialized memory buffers. Uninitialized buffers may contain residual data from the same Node.js process — including data from prior requests, tasks, secrets, or tokens — resulting in information disclosure of sensitive in-process data. Task Runners must be enabled using N8NRUNNERSENABLED=true. In external runner mode, the impact is limited to data within the external runner process. The issue has been fixed in n8n versions 1.123.22, 2.10.1 , and 2.9.3. Users should upgrade to this version or later to remediate the vulnerability. If upgrading is not immediately possible, administrators should consider the following temporary mitigations: Limit workflow creation and editing permissions to fully trusted users only, and/or use external runner mode (N8NRUNNERSMODE=external) to isolate the runner process. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
— MITRE
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2026-27496?
CVE-2026-27496 is considered a high severity vulnerability due to its potential for memory disclosure.
How do I fix CVE-2026-27496?
You can fix CVE-2026-27496 by upgrading n8n to version 2.9.3, 2.10.1, or 1.123.22.
Who is affected by CVE-2026-27496?
Authenticated users with permission to create or modify workflows in n8n are affected by CVE-2026-27496.
What kind of data could be disclosed due to CVE-2026-27496?
CVE-2026-27496 can leak residual data from uninitialized memory buffers possibly including sensitive information.
Which versions of n8n are vulnerable to CVE-2026-27496?
Versions of n8n from 2.0.0-rc.0 up to 2.10.0 and any below 1.123.22 are vulnerable to CVE-2026-27496.