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CVE-2026-0863

CRITICALCVSS 9.9/10EPSS 8.50%

Last modified

CVE-2026-0863 is a critical-severity vulnerability rated 9.9/10 on the CVSS scale. 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.. EPSS estimates a 8.50% chance of exploitation in the next 30 days.

Description

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.

Metrics

CVSS 3.1
9.9/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H

EPSS Probability
8.50%

94.3th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
N8nN8n<= 1.123.14
N8nN8n>= 2.0.0, <= 2.3.5
N8nN8n>= 2.4.0, <= 2.4.2

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-0863?
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.
How severe is CVE-2026-0863?
CVE-2026-0863 has a CVSS score of 9.9/10 (CRITICAL severity). The EPSS model estimates a 8.50% probability of exploitation in the next 30 days.
How do I fix CVE-2026-0863?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

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Source: NVD / NIST