CVE-2026-5842: 9router Decolua 9router Vulnerable To Authorization Vulnerability

MODERATE
Advisory Identifier: GHSA-xrrh-p7f2-27vm
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CVSS 7.3
CWE-285
Published
Advisory Summary

CVE-2026-5842 is a MODERATE (CVSS 7.3) decolua 9router vulnerable to authorization vulnerability (CWE-285: Improper Authorization) affecting 9router libraries in the npm ecosystem. The issue involves decolua 9router vulnerable to authorization bypass. Remediation is available by upgrading affected packages to version 0.3.75.

CVE-2026-5842 at a Glance

CVE Identifier CVE-2026-5842
GHSA Identifier GHSA-xrrh-p7f2-27vm
Severity MODERATE
CVSS v3.1 Base Score 7.3
CWE Classification CWE-285: Improper Authorization
Affected Product 9router
Package Ecosystem npm
Published Date
Last Updated

Security Impact

CVSS: 7.3

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L).

Attack Vector Network (AV:N)
Attack Complexity Low (AC:L)
Privileges Required None (PR:N)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity Low (I:L)
Availability Low (A:L)

How to Fix CVE-2026-5842

To remediate this vulnerability, upgrade all affected 9router dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

9router fixed: 0.3.75 
npm install 9router@0.3.75
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 9router

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-5842, inspect your project dependencies using npm:

npm ls 9router

Analyze the terminal output to locate any version of 9router in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 0.3.75), your application is affected.

Note: The npm ls 9router 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-285: Improper Authorization, where the product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action. In 9router, 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

A security vulnerability has been detected in decolua 9router up to 0.3.47. The impacted element is an unknown function of the file /api of the component Administrative API Endpoint. The manipulation leads to authorization bypass. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.75 is sufficient to resolve this issue. It is suggested to upgrade the affected component.

CVE-2026-5842 Affected 9router Versions

1 component(s)
Fixed Versions:
0.3.75
Product / Package Ecosystem Affected Versions Fixed Version
9router
npm/9router
npm
< 0.3.75
0.3.75

References

NVD — CVE-2026-5842 NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-5842
9router Source Repository REPOSITORY
https://github.com/decolua/9router/issues/431
9router Source Repository REPOSITORY
https://github.com/decolua/9router/issues/431#issuecomment-4140163867
9router Source Repository REPOSITORY
https://github.com/decolua/9router
9router Release RELEASE
https://github.com/decolua/9router/releases/tag/v0.3.75
9router Source Repository REPOSITORY
https://github.com/deepcat1337/Free_Api_Exploit/tree/main
vuldb.com/submit/790003 WEB
https://vuldb.com/submit/790003
vuldb.com/vuln/356298 WEB
https://vuldb.com/vuln/356298
vuldb.com/vuln/356298/cti WEB
https://vuldb.com/vuln/356298/cti

Frequently Asked Questions

What is CVE-2026-5842?
CVE-2026-5842 is a security vulnerability in 9router involving decolua 9router vulnerable to authorization bypass under CWE-285: Improper Authorization.
Which 9router versions are affected?
Affected versions include releases prior to 0.3.75 across affected packages: 9router.
What version fixes CVE-2026-5842?
Upgrading to 0.3.75 (or the latest patched release for your respective branch) resolves the vulnerability.
Is 9router affected?
Yes, 9router is affected in releases prior to 0.3.75. Upgrade your dependency to 0.3.75 or later.
What is the CVSS score of CVE-2026-5842?
CVE-2026-5842 has a CVSS v3.1 base score of 7.3 (MODERATE) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
What CWE is associated with CVE-2026-5842?
CVE-2026-5842 is classified under CWE-285: Improper Authorization (The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.).
How can I check npm dependencies for CVE-2026-5842?
Run the dependency tree command: 'npm ls 9router'. 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-xrrh-p7f2-27vm",
  "modified" : "2026-04-10T19:20:27Z",
  "published" : "2026-04-09T06:30:28Z",
  "aliases" : [ "CVE-2026-5842" ],
  "summary" : "decolua 9router vulnerable to authorization bypass",
  "details" : "A security vulnerability has been detected in decolua 9router up to 0.3.47. The impacted element is an unknown function of the file /api of the component Administrative API Endpoint. The manipulation leads to authorization bypass. The attack is possible to be carried out remotely. The exploit has been disclosed publicly and may be used. Upgrading to version 0.3.75 is sufficient to resolve this issue. It is suggested to upgrade the affected component.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
  }, {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "9router"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.3.75"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2026-5842"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/issues/431"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/issues/431#issuecomment-4140163867"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/decolua/9router"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/decolua/9router/releases/tag/v0.3.75"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/deepcat1337/Free_Api_Exploit/tree/main"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/submit/790003"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/356298"
  }, {
    "type" : "WEB",
    "url" : "https://vuldb.com/vuln/356298/cti"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-285" ],
    "severity" : "MODERATE",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-04-10T19:20:27Z",
    "nvd_published_at" : "2026-04-09T05:16:06Z"
  }
}