CVE-2026-86076
n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
What an attacker can affect
- Confidentiality
- High
- Integrity
- High
- Availability
- High
Exploit likelihood
What each source reports
CVE List Score used
n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
- Record
CVE-2026-86076- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N - Weakness
- CWE-94
- Updated
- 2026-11-02
EUVDEUVD-2026-74280
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
- Record
EUVD-2026-74280- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-hw8v-xxg5-vvvx
n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution
Impact
The expression compiler's sanitizer resolved through a dynamically-scoped this, so a class field named __sanitize rebound it and reached the Function constructor. On the backend, any expression author could run code in the n8n process; in the editor preview, a member's expression could run as JavaScript in the session of whoever opened the workflow. The patch rejects reserved class-member names.
Patches
The issue has been fixed in n8n versions 1.123.76, 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.
- Avoid granting workflow-create or workflow-edit permissions to untrusted users.
- Audit existing workflows for unexpected or unfamiliar expressions in node parameters.
- Set
N8N_EXPRESSION_ENGINE=vm.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-hw8v-xxg5-vvvx- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N - Weakness
- CWE-94
- Updated
- 2026-11-02
NVD
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
- Record
CVE-2026-86076- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 8.8 High
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H - Weakness
- CWE-94
- Updated
- 2026-11-02
OSV
n8n: Expression Sandbox Escape in Editor-UI Enables Stored Cross-User JavaScript Execution
n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the expression compiler sanitizer resolved through dynamically scoped this and did not reject reserved class member names. A class field named __sanitize could rebind the sanitizer and reach the Function constructor, enabling backend code execution and editor-preview JavaScript execution. The affected AST hook is PrototypeSanitizer in packages/workflow/src/expression-sandboxing.ts. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.
- Record
CVE-2026-86076- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N - Weakness
- CWE-94
- Updated
- 2026-11-02
OSVGHSA-hw8v-xxg5-vvvx
n8n: Expression Sandbox Escape via Class-Field Sanitizer Rebinding Can Lead to Code Execution
Impact
The expression compiler's sanitizer resolved through a dynamically-scoped this, so a class field named __sanitize rebound it and reached the Function constructor. On the backend, any expression author could run code in the n8n process; in the editor preview, a member's expression could run as JavaScript in the session of whoever opened the workflow. The patch rejects reserved class-member names.
Patches
The issue has been fixed in n8n versions 1.123.76, 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.
- Avoid granting workflow-create or workflow-edit permissions to untrusted users.
- Audit existing workflows for unexpected or unfamiliar expressions in node parameters.
- Set
N8N_EXPRESSION_ENGINE=vm.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
- Record
GHSA-hw8v-xxg5-vvvx- CVSS 4.0
- 8.7 High
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:H/SI:N/SA:N - Weakness
- CWE-94
- Updated
- 2026-11-02
OSVROOT-APP-NPM-CVE-2026-86076 No score
CVE-2026-86076 in n8n - Patched by Root
Root has patched CVE-2026-86076 in the n8n package for Root:npm. Multiple fixed versions available.
- Record
ROOT-APP-NPM-CVE-2026-86076- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
n8nnpm |
before 1.123.76 | 1.123.76 |
n8nnpm |
2.38.0 up to 2.38.2 | 2.38.2 |
n8nnpm |
2.0.0 up to 2.37.7 | 2.37.7 |
n8nRoot:npm |
before 2.19.3-aikido.10 | 2.19.3-aikido.102.19.3-aikido.112.19.3-aikido.122.19.3-aikido.132.19.3-aikido.142.19.3-aikido.15 |
@rootio/n8nRoot:npm |
before 2.19.3-root.io.10 | 2.19.3-root.io.102.19.3-root.io.112.19.3-root.io.122.19.3-root.io.132.19.3-root.io.142.19.3-root.io.15 |
Public exploits
Links only. Every CVE stores no exploit code.
| Source | Link | Date |
|---|---|---|
| PoC in GitHub | Boreas37/CVE-2026-86076-PoC | 2026-10-24 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV, PoC in GitHub |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-86076 is a high vulnerability (CVSS 8.7) in N8n, published September 8, 2026. Public exploit code exists. EPSS puts the chance of exploitation in the next 30 days at 0.65%, the 51st percentile. Fixed in n8n 1.123.76.
References
github.com/n8n-io/n8n/security/advisories/GHSA-hw8v-xxg5-vvvx
nvd.nist.gov/vuln/detail/CVE-2026-86076