CVE-2026-65591: n8n before 1.123.64 Sanitizer Bypass Remote Code Execution
Impact The legacy expression evaluator's computed-member sanitizer can be bypassed by an authenticated user with workflow create or modify permissions. Successful exploitation grants the attacker host-level code execution as the n8n process.
The legacy expression engine is the default engine in affected versions.
Patches 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.
Workarounds If upgrading is not immediately possible, administrators should consider the following temporary mitigations: - Restrict n8n instance access to fully trusted users only. - Switch to the non-legacy expression engine by setting N8NEXPRESSIONENGINE=vm.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Other sources
n8n contains a sanitizer bypass vulnerability in the legacy expression evaluator's computed-member handler. An authenticated user with workflow create or modify permissions can craft a malicious expression to bypass the sanitizer and achieve host-level code execution as the n8n process. The legacy expression engine is the default in affected versions. Fixed in n8n 1.123.64, 2.29.8, and 2.30.1.
— MITRE
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.29.8 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 2.30.1 - Upgrade
Upgrade
npm/n8nto a version that resolves this vulnerability.Fixed in 1.123.64 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 1.123.64 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.29.8 - Upgrade
Upgrade
n8nto a version that resolves this vulnerability.Fixed in 2.30.1 - Configuration
Switch to the non-legacy expression engine by setting N8N_EXPRESSION_ENGINE=vm (temporary mitigation if immediate upgrade is not possible).
n8n N8N_EXPRESSION_ENGINE = vm - Compensating control
Restrict access to the n8n instance to fully trusted users only (temporary mitigation if immediate upgrade is not possible).
Event History
Frequently Asked Questions
What is the severity of CVE-2026-65591?
CVE-2026-65591 has been rated with a severity score of high at 8.9 according to the CVSS.
How does CVE-2026-65591 affect n8n?
CVE-2026-65591 allows an authenticated user with workflow permissions to bypass the sanitizer, leading to remote code execution on the host.
What are the potential risks of CVE-2026-65591?
The exploitation of CVE-2026-65591 can lead to host-level code execution, compromising the integrity and security of the affected n8n instance.
How can I fix CVE-2026-65591?
To fix CVE-2026-65591, users should update to n8n version 1.123.64 or later, which includes mitigations for this vulnerability.
Who is affected by CVE-2026-65591?
Any authenticated user with permissions to create or modify workflows in n8n versions before 1.123.64 is at risk from CVE-2026-65591.