Vulnerability-Lookup

GHSA-6XCW-7XM6-48C6

Vulnerability from github – Published: 2026-09-10 20:37 – Updated: 2026-09-10 20:37

Summary

n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution

Details

Impact

Two stages of expression code generation built source text by calling the global JSON.stringify at generation time: the compiler when printing synthetic string literals, and the isolate bridge when interpolating a timezone value into its per-evaluation wrapper. An expression that replaced that global therefore changed the code that was subsequently generated and executed, turning literal data into executable source. The patch renders both code-generation stages through a reference captured at module load, so a later change to global state cannot alter the generated source.

This vulnerability only affects instances running the legacy expression engine. The vm expression engine, which is the default on the patched releases, is not affected.

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: - Set the environment variable N8N_EXPRESSION_ENGINE=vm to switch to the vm expression engine, which is not affected by this vulnerability. - Restrict n8n instance access to fully trusted users only. - Ensure the n8n process runs under a dedicated low-privilege OS user account to limit the impact of any command execution.

These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

Severity

7.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.123.76"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.38.0"
            },
            {
              "fixed": "2.38.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "n8n"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.37.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-86083"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-94"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-09-10T20:37:21Z",
    "nvd_published_at": "2026-09-08T22:19:17Z",
    "severity": "HIGH"
  },
  "details": "## Impact\n\nTwo stages of expression code generation built source text by calling the global `JSON.stringify` at generation time: the compiler when printing synthetic string literals, and the isolate bridge when interpolating a timezone value into its per-evaluation wrapper. An expression that replaced that global therefore changed the code that was subsequently generated and executed, turning literal data into executable source. The patch renders both code-generation stages through a reference captured at module load, so a later change to global state cannot alter the generated source.\n\nThis vulnerability only affects instances running the legacy expression engine. The `vm` expression engine, which is the default on the patched releases, is not affected.\n\n## Patches\n\nThe 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.\n\n## Workarounds\n\nIf upgrading is not immediately possible, administrators should consider the following temporary mitigations:\n- Set the environment variable `N8N_EXPRESSION_ENGINE=vm` to switch to the vm expression engine, which is not affected by this vulnerability.\n- Restrict n8n instance access to fully trusted users only.\n- Ensure the n8n process runs under a dedicated low-privilege OS user account to limit the impact of any command execution.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
  "id": "GHSA-6xcw-7xm6-48c6",
  "modified": "2026-09-10T20:37:22Z",
  "published": "2026-09-10T20:37:21Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/security/advisories/GHSA-6xcw-7xm6-48c6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-86083"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/n8n-io/n8n"
    },
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76"
    },
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7"
    },
    {
      "type": "WEB",
      "url": "https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution"
}

CVE-2026-86083 (GCVE-0-2026-86083)

Vulnerability from cvelistv5 – Published: 2026-09-08 21:22 – Updated: 2026-09-09 13:24

Title

n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution

Summary

n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the legacy expression engine generated source text by calling the mutable global JSON.stringify while printing synthetic string literals and interpolating timezone data. An expression could replace JSON.stringify and cause later generated source to contain executable attacker-controlled code. The affected code-generation paths include packages/@n8n/expression-runtime/src/bridge/isolated-vm-bridge.ts and packages/@n8n/tournament/src/ExpressionBuilder.ts, and the issue does not affect the vm expression engine. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2.

Severity

7.7 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N

SSVC

Exploitation: none Automatable: no Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-09-09 13:24 UTC

CWE

CWE-94 - Improper Control of Generation of Code ('Code Injection')

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/n8n-io/n8n/security/advisories…	x_refsource_CONFIRM
https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76	x_refsource_MISC
https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7	x_refsource_MISC
https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
n8n-io	n8n	Affected: >= 2.38.0, < 2.38.2 Affected: >= 2.0.0, < 2.37.7 Affected: < 1.123.76

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JSON

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{
  "containers": {
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      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-86083",
                "options": [
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                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-09-09T13:24:48.914936Z",
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          "shortName": "CISA-ADP"
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      "descriptions": [
        {
          "lang": "en",
          "value": "n8n is an open source workflow automation platform. Prior to 1.123.76, 2.37.7, and 2.38.2, the legacy expression engine generated source text by calling the mutable global JSON.stringify while printing synthetic string literals and interpolating timezone data. An expression could replace JSON.stringify and cause later generated source to contain executable attacker-controlled code. The affected code-generation paths include packages/@n8n/expression-runtime/src/bridge/isolated-vm-bridge.ts and packages/@n8n/tournament/src/ExpressionBuilder.ts, and the issue does not affect the vm expression engine. This issue is fixed in versions 1.123.76, 2.37.7 and 2.38.2."
        }
      ],
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            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
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      "title": "n8n: Expression Sandbox Escape via Shared Builtin Tampering and Code-Printer Injection Leads to Code Execution"
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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.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.