Vulnerability in n8n (CVE-2026-86078)
Summary
Vulnerability in n8n (CVE-2026-86078). Risk of unauthorized operations or information disclosure. Exploitable via __proto__. Mitigation: upgrade to 2.37.7 or later.
Original description
The description as published by the source.
Impact
The Instance AI workflow summary built its result with get-or-create-then-nested-write idioms keyed by node names and connection keys taken from the stored workflow. Those are arbitrary strings: the restricted-name guard n8n shows in the editor is client-side and is bypassed by posting the workflow to the REST API directly. So a reserved key such as __proto__ resolved up the prototype chain instead of creating an own key, and the write landed on Object.prototype in the main n8n process, affecting every later request. The patch builds the summary with null-prototype accumulators and validates the keys it accepts, so reserved names cannot reach the prototype chain.
Patches
The issue has been fixed in n8n versions 2.37.7 and 2.38.2. 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.
- Remove or leave unconfigured the
N8N_INSTANCE_AI_MODEL*environment variables to prevent the Instance AI module from reaching the vulnerable code path. - Restart the n8n process to clear any in-memory prototype pollution if an attack is suspected.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
Source: NIST National Vulnerability Database NVD GitHub Advisory
Auto-generated summary
Assembled by SecPulse from the source data (CVSS, CWE, affected versions) using templates — no AI involved. Check the original description and references below for exact details.
A vulnerability tracked as CVE-2026-86078 has been found in n8n.
Attackers can target a specific entry point like __proto__ over the network to misuse the product.
Risk of unauthorized operations or information disclosure. CVSS score: 6.5/10.
What to do: upgrade n8n to 2.37.7 or later.
If unsure, ask your IT team or search "n8n CVE-2026-86078" on the vendor's site.
CVE-2026-86078 (n8n) — CWE-1321 / CVSS v3 6.5
Attack vector: remote (network-reachable) / no user interaction
Attack surface: __proto__ / Object.prototype
Patched: 2.37.7 — apply immediately
Plan: 1) Audit SBOM/dependencies, 2) Stage→prod upgrade, 3) Add WAF/proxy monitoring on affected endpoints, 4) Hunt IOCs in logs.
Refs: see the GHSA / vendor advisory / patched release linked on this page.
A vulnerability (CWE-1321) exists in n8n. Attackers reach the vulnerable code path via __proto__.
Check the vendor advisory for the affected versions of n8n. Attack surface: __proto__ / Object.prototype.
Severity: Medium (CVSS 6.5/10). Risk of unauthorized operations or information disclosure.
Update to 2.37.7.
Until the patch is applied: disable the affected feature, apply WAF rules, or restrict access via network ACLs.
Search webserver/proxy logs for unusual request patterns matching this CVE's known IOCs. Run grep -r 'n8n' . against your dependency files (package-lock.json, requirements.txt, go.sum) to find affected services.
Response actions
Concrete steps and command examples for SOC/SRE teams to execute in order
-
1Identify exposure identify
grep -r 'n8n' . | grep -v node_modulesリポジトリと本番環境の依存ファイル (package-lock.json / requirements.txt / go.sum / Gemfile.lock 等) で
n8nを grep し、稼働しているサービス・バージョンを把握する。 -
2Apply patch patch
Upgrade n8n to 2.37.7ステージング環境で 2.37.7 に上げて回帰テスト → 本番反映。回帰テストはアプリの主要ハッピーパスを含めること。
-
3Post-deployment verification verify
Confirm patched version is live in productionパッチ適用後、ステージングで PoC または同等の悪用パターンを再現して脆弱性が閉じたことを確認。本番ではアクセスログ・WAF でアラート再発が無いか継続監視。
Affected packages
References
- web github.com
- web github.com
- web github.com
- web nvd.nist.gov
- web github.com