n8n hat einen Sandbox Escape in seinem JavaScript Task Runner

The core of the vulnerability lies within the JavaScript Task Runner sandbox. An attacker, already authenticated and possessing the ability to create or modify workflows, can craft malicious workflows that bypass the intended sandbox restrictions. This allows them to execute arbitrary code outside of the sandbox’s boundaries. The severity of the impact is directly tied to the Task Runner mode. When using the default internal Task Runner mode, the attacker gains complete control over the n8n host, enabling them to execute commands, access sensitive data, and potentially pivot to other systems on the network. Even with external Task Runners, the attacker can impact or gain access to other tasks executed on the Task Runner, representing a significant security risk. This vulnerability is particularly concerning given n8n's use in automating sensitive business processes.

Organizations heavily reliant on n8n for workflow automation, particularly those using the default internal Task Runner configuration, are at significant risk. Environments where user access controls are not strictly enforced, allowing unauthorized users to create or modify workflows, are especially vulnerable.

• nodejs / server:

ps aux | grep n8n

Check for unusual processes running within the n8n environment. • nodejs / server:

journalctl -u n8n -f | grep -i error

Monitor n8n logs for error messages or suspicious activity related to task execution. • generic web:

curl -I http://<n8n_host>/ | grep -i 'n8n/1.123.22'

Verify the n8n version is patched (1.123.22 or later).

1. 2026-02-25Disclosure

   disclosure

1. Reserviert2026-02-19
2. Veröffentlicht2026-02-25
3. Geändert2026-02-28
4. EPSS aktualisiert2026-03-23

The primary mitigation for CVE-2026-27495 is to upgrade to a patched version of n8n. Versions 1.123.22, 2.9.3, and 2.10.1 contain the necessary fixes. If immediate upgrading is not feasible, consider disabling Task Runners entirely by setting N8NRUNNERSENABLED=false. This will prevent the execution of JavaScript tasks but will also impact functionality that relies on them. As a temporary workaround, restrict user permissions to prevent users from creating or modifying workflows, limiting the attack surface. Monitor n8n logs for suspicious activity related to workflow execution and Task Runner processes. Implement a Web Application Firewall (WAF) with rules to detect and block malicious workflow payloads.