CVE-2026-0863: Sandbox escape in n8n Python task runner allows for arbitrary code execution on the underlying host.
Using string formatting and exception handling, an attacker may bypass n8n's python-task-executor sandbox restrictions and run arbitrary unrestricted Python code in the underlying operating system.
The vulnerability can be exploited via the Code block by an authenticated user with basic permissions and can lead to a full n8n instance takeover on instances operating under "Internal" execution mode.
If the instance is operating under the "External" execution mode (ex. n8n's official Docker image) - arbitrary code execution occurs inside a Sidecar container and not the main node, which significantly reduces the vulnerability impact.
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2026-0863?
CVE-2026-0863 has been classified as a high severity vulnerability due to its potential for arbitrary code execution.
How do I fix CVE-2026-0863?
To mitigate CVE-2026-0863, update n8n to the latest version where the vulnerability has been patched.
What type of vulnerability is CVE-2026-0863?
CVE-2026-0863 is a sandbox escape vulnerability affecting the Python task runner in n8n.
What could an attacker do with CVE-2026-0863?
An attacker exploiting CVE-2026-0863 could execute arbitrary Python code on the underlying host system.
Which software is affected by CVE-2026-0863?
CVE-2026-0863 affects n8n, specifically the Python task runner component.