GHSA-HX4H-VR3M-45VH
Vulnerability from github – Published: 2026-07-22 22:13 – Updated: 2026-07-22 22:13Impact
An authenticated user able to create or edit a workflow expression could abuse the expression engine's array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service.
Both self-hosted and cloud instances running the VM expression engine are affected.
Patches
The issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. 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. - Disable the VM expression engine if an alternative is available for your deployment.
These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.
{
"affected": [
{
"package": {
"ecosystem": "npm",
"name": "n8n"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "1.123.67"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "n8n"
},
"ranges": [
{
"events": [
{
"introduced": "2.32.0"
},
{
"fixed": "2.32.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "npm",
"name": "n8n"
},
"ranges": [
{
"events": [
{
"introduced": "2.0.0-rc.0"
},
{
"fixed": "2.31.5"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [],
"database_specific": {
"cwe_ids": [
"CWE-1321"
],
"github_reviewed": true,
"github_reviewed_at": "2026-07-22T22:13:04Z",
"nvd_published_at": null,
"severity": "MODERATE"
},
"details": "## Impact\n\nAn authenticated user able to create or edit a workflow expression could abuse the expression engine\u0027s array-element access to obtain a reference to a host built-in and pollute its prototype in the main n8n process, leading to a denial of service.\n\nBoth self-hosted and cloud instances running the VM expression engine are affected.\n\n## Patches\n\nThe issue has been fixed in n8n versions 1.123.67, 2.31.5, and 2.32.1. Users should upgrade to one of these versions or later to remediate the vulnerability.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Restrict n8n instance access to fully trusted users only.\n- Disable the VM expression engine if an alternative is available for your deployment.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
"id": "GHSA-hx4h-vr3m-45vh",
"modified": "2026-07-22T22:13:04Z",
"published": "2026-07-22T22:13:04Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-hx4h-vr3m-45vh"
},
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/commit/f69dfc6dd2178a14ea1624d2e1d403c2e755042f"
},
{
"type": "PACKAGE",
"url": "https://github.com/n8n-io/n8n"
},
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.67"
},
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/releases/tag/n8n@2.31.5"
},
{
"type": "WEB",
"url": "https://github.com/n8n-io/n8n/releases/tag/n8n@2.32.1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "n8n: Prototype Pollution via VM Expression Engine Sandbox Escape Leads to Denial of Service"
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.