GHSA-49mx-fj45-q3p6
HIGHn8n's Unsafe Buffer Allocation Allows In-Process Memory Disclosure in Task Runner
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
Weekly download volume for affected packages — a proxy for how broadly this vulnerability is deployed.
n8nnpmDescription
Impact
The use of Buffer.allocUnsafe() and Buffer.allocUnsafeSlow() in the task runner allowed untrusted code to allocate uninitialized memory. Such uninitialized buffers could contain residual data from within the same Node.js process (for example, data from prior requests, tasks, secrets, or tokens), resulting in potential information disclosure.
Only authenticated users are able to execute code through Task Runners.
This issue affected any deployment in which both of the following conditions were met:
- Task Runners were enabled using
N8N_RUNNERS_ENABLED=true(default: false) - Code Node was enabled (default: true)
Patches
Access to unsafe Buffer functions has been removed from the task runner sandbox. All buffer allocations are now zero-filled by default.
- Fixed in: 1.114.3 & 1.115.0
- Action: It is strongly recommended to upgrade to version ≥ 1.114.3 as soon as possible.
Changes introduced in this patch include:
- Routing all buffer allocations through
Buffer.alloc(which zero-fills) operations where applicable - Adding regression tests to ensure continued enforcement of safe allocation practices
Workarounds
If an immediate upgrade cannot be applied, the following hardening steps are recommended:
- Disable the Code Node by adding
n8n-nodes-base.codeto theNODES_EXCLUDEenvironment variable - Prefer external mode for isolation: run Task Runners in external mode so that untrusted task code executes in a separate sidecar container rather than within the main n8n process. This configuration significantly reduces the risk of in-process memory disclosure caused by unsafe buffer allocations.
In external mode, a launcher manages Task Runner processes in a dedicated sidecar environment, separate from the primary n8n instance.
See the n8n documentation for configuration details and required environment variables.
Resources
- Node.js documentation:
Buffer.alloc()vsBuffer.allocUnsafe()— background on zero-filled vs uninitialized allocations - n8n Documentation — Task Runners — external mode, setup guide, and environment configuration details
- n8n Documentation — Blocking nodes — how to globally disable specific nodes
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | n8n | ≥ 1.65.0&&< 1.114.3 | 1.114.3 |
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 1.114.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-49mx-fj45-q3p6 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-49mx-fj45-q3p6 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-49mx-fj45-q3p6. 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-49mx-fj45-q3p6 in your dependencies?
O3 detects GHSA-49mx-fj45-q3p6 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.