GHSA-pm35-fqvh-cq5g
n8n: Legacy Expression Evaluator Sanitizer Bypass Leads to Authenticated Code Execution
Blast Radius
n8n📦n8n📦n8nReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
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.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n | all versions | 1.123.64 |
| 📦npm | n8n | ≥ 2.30.0&&< 2.30.1 | 2.30.1 |
| 📦npm | n8n | ≥ 2.0.0-rc.0&&< 2.29.8 | 2.29.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for n8n. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update n8n to 1.123.64 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-pm35-fqvh-cq5g is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-pm35-fqvh-cq5g is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-pm35-fqvh-cq5g. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-pm35-fqvh-cq5g in your dependencies?
O3 detects GHSA-pm35-fqvh-cq5g across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.