n8n: Legacy Expression Evaluator Sanitizer Bypass Leads to Authenticated 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 `N8N_EXPRESSION_ENGINE=vm`. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Source published

22 Jul 2026 22:02:04 UTC

Source modified

22 Jul 2026 22:26:48 UTC

Observed here

24 Oct 2026 13:17:17 UTC

Source terms

GitHub Advisory Database · CC-BY-4.0

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This view projects the publisher's source fields for reading; the original JSON retains additional fields and CVE enrichment containers. Attribution: osv · GitHub Advisory Database · CC-BY-4.0. Source text is retained; field grouping and change labels are provided by ChangeIntel.

CVSS_V4 · CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:L

Publisher rating · HIGH