CVE-2026-86081: n8n Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-j535-v25q-vx3q
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CWE-1333
Published
Advisory Summary

CVE-2026-86081 is a HIGH denial of service vulnerability (CWE-1333: Inefficient Regular Expression Complexity) affecting n8n libraries in the npm ecosystem. The issue involves regular expression denial of service in the default blocked-file-pattern match via a git node clone path. Remediation is available by upgrading affected packages to version 1.123.76, 2.38.2, 2.37.7.

CVE-2026-86081 at a Glance

CVE Identifier CVE-2026-86081
GHSA Identifier GHSA-j535-v25q-vx3q
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-1333: Inefficient Regular Expression Complexity
Affected Product n8n
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-86081

To remediate this vulnerability, upgrade all affected n8n dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

n8n fixed: 1.123.76 
npm install n8n@1.123.76
n8n fixed: 2.38.2 
npm install n8n@2.38.2
n8n fixed: 2.37.7 
npm install n8n@2.37.7
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

npm ls n8n

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-86081, inspect your project dependencies using npm:

npm ls n8n

Analyze the terminal output to locate any version of n8n in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.123.76), your application is affected.

Note: The npm ls n8n command inspects dependencies declared in your package.json and lockfile; it does not perform automated runtime dynamic scanning.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-1333: Inefficient Regular Expression Complexity, where the product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential. In n8n, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

## Impact The Git node's clone operation matched the destination path against the default `N8N_BLOCK_FILE_PATTERNS` expression, which was written so that a crafted path caused catastrophic backtracking. Evaluation runs synchronously in the main n8n process, so an authenticated user could freeze the instance for everyone with a single workflow execution and no unusual configuration. The patch rewrites the pattern so that matching is linear in the length of the path. ## 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. - Disable the Git node by adding `n8n-nodes-base.git` to the `NODES_EXCLUDE` environment variable. - Set `N8N_BLOCK_FILE_PATTERNS` to a backtracking-safe equivalent pattern to replace the vulnerable default. These workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.

CVE-2026-86081 Affected n8n Versions

3 component(s)
Fixed Versions:
1.123.762.38.22.37.7
Product / Package Ecosystem Affected Versions Fixed Version
n8n
npm/n8n
npm
< 1.123.76
1.123.76
n8n
npm/n8n
npm
≥ 2.38.0
< 2.38.2
2.38.2
n8n
npm/n8n
npm
≥ 2.0.0
< 2.37.7
2.37.7

References

GitHub Advisory / Wiki ADVISORY
https://github.com/n8n-io/n8n/security/advisories/GHSA-j535-v25q-vx3q
NVD — CVE-2026-86081 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-86081
n8n Source Repository REPOSITORY
https://github.com/n8n-io/n8n
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@1.123.76
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.37.7
n8n Release RELEASE
https://github.com/n8n-io/n8n/releases/tag/n8n@2.38.2

Frequently Asked Questions

What is CVE-2026-86081?
CVE-2026-86081 is a security vulnerability in n8n involving Regular Expression Denial of Service in the Default Blocked-File-Pattern Match via a Git Node Clone Path under CWE-1333: Inefficient Regular Expression Complexity.
Which n8n versions are affected?
Affected versions include releases prior to 1.123.76, 2.38.2, 2.37.7 across affected packages: n8n.
What version fixes CVE-2026-86081?
Upgrading to 1.123.76, 2.38.2, 2.37.7 (or the latest patched release for your respective branch) resolves the vulnerability.
Is n8n affected?
Yes, n8n is affected in releases prior to 1.123.76, 2.38.2, 2.37.7. Upgrade your dependency to 1.123.76, 2.38.2, 2.37.7 or later.
What CWE is associated with CVE-2026-86081?
CVE-2026-86081 is classified under CWE-1333: Inefficient Regular Expression Complexity (The product uses a regular expression with a worst-case computational complexity that is inefficient and possibly exponential.).
How can I check npm dependencies for CVE-2026-86081?
Run the dependency tree command: 'npm ls n8n'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-j535-v25q-vx3q",
  "modified" : "2026-09-10T15:12:00Z",
  "published" : "2026-09-10T15:12:00Z",
  "aliases" : [ "CVE-2026-86081" ],
  "summary" : "n8n: Regular Expression Denial of Service in the Default Blocked-File-Pattern Match via a Git Node Clone Path",
  "details" : "## Impact\n\nThe Git node's clone operation matched the destination path against the default `N8N_BLOCK_FILE_PATTERNS` expression, which was written so that a crafted path caused catastrophic backtracking. Evaluation runs synchronously in the main n8n process, so an authenticated user could freeze the instance for everyone with a single workflow execution and no unusual configuration. The patch rewrites the pattern so that matching is linear in the length of the path.\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- Restrict n8n instance access to fully trusted users only.\n- Disable the Git node by adding `n8n-nodes-base.git` to the `NODES_EXCLUDE` environment variable.\n- Set `N8N_BLOCK_FILE_PATTERNS` to a backtracking-safe equivalent pattern to replace the vulnerable default.\n\nThese workarounds do not fully remediate the risk and should only be used as short-term mitigation measures.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "1.123.76"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.38.0"
      }, {
        "fixed" : "2.38.2"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "npm",
      "name" : "n8n"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "2.0.0"
      }, {
        "fixed" : "2.37.7"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/n8n-io/n8n/security/advisories/GHSA-j535-v25q-vx3q"
  }, {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-86081"
  }, {
    "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-1333" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-09-10T15:12:00Z",
    "nvd_published_at" : "2026-09-08T22:19:17Z"
  }
}