CVE-2025-61917 is a high-severity (CVSS 7.7) Information Exposure vulnerability in n8n. A fix is available for n8n — see the affected versions and patch details below.
n8n Unsafe Buffer Allocation Allows In-Process Memory Disclosure in Task Runner
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-61917.
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.
How urgent is this, really
CVE-2025-61917 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,636 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.
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 | 1.114.3npm install n8n@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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update n8n to 1.114.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-61917 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2025-61917 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-61917. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2025-61917 in your dependencies?
O3 Security finds CVE-2025-61917 across npm dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.