CVE-2026-43946: Fuxa server FUXA Has An Unauthenticated Arbitrary Vulnerability

HIGH
Advisory Identifier: GHSA-fwcm-rqvw-j3p7
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CWE-863
Published
Advisory Summary

CVE-2026-43946 is a HIGH fuxa has an unauthenticated arbitrary vulnerability (CWE-863: Incorrect Authorization) affecting Fuxa server libraries in the npm ecosystem. The issue involves fuxa has an unauthenticated arbitrary tag value disclosure via /api/gettagvalue. Remediation is available by upgrading affected packages to version 1.3.1.

CVE-2026-43946 at a Glance

CVE Identifier CVE-2026-43946
GHSA Identifier GHSA-fwcm-rqvw-j3p7
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-863: Incorrect Authorization
Affected Product Fuxa server
Package Ecosystem npm
Published Date
Last Updated

How to Fix CVE-2026-43946

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

fuxa-server fixed: 1.3.1 
npm install fuxa-server@1.3.1
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 fuxa-server

How to Check if You Are Affected

To determine whether your Node.js application is affected by CVE-2026-43946, inspect your project dependencies using npm:

npm ls fuxa-server

Analyze the terminal output to locate any version of Fuxa server in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 1.3.1), your application is affected.

Note: The npm ls fuxa-server 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-863: Incorrect Authorization, where the product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check. In Fuxa server, 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

### Summary An authorization bypass in the /api/getTagValue endpoint allows unauthenticated access to tag values when the referenced script does not exist. ### Details The issue is caused by the combination of these code paths: - `server/api/apikeys/verify-api-or-token.js:45` sends requests without `x-api-key` to `authJwt.verifyToken(req, res, next)`. - `server/api/jwt-helper.js:46-64` creates a signed guest token when no `x-access-token` is provided: `if (!token) { token = getGuestToken(); }` and then populates `req.userId` / `req.userGroups` from that guest token. - `server/api/command/index.js:76-105` exposes `/api/getTagValue`. - `server/runtime/scripts/index.js:106-111` returns `true` when the referenced script does not exist: `if (!script) { return true; }` As a result, an unauthenticated request reaches `/api/getTagValue` as `guest`, and the authorization check is bypassed because `isAuthorisedByScriptName()` returns `true` when `sourceScriptName` is omitted or does not match a real script. The endpoint then returns arbitrary tag values by ID. ### PoC Requests to /api/getTagValue without authentication could succeed when the authorization logic evaluated a non-existent sourceScriptName as authorized.

CVE-2026-43946 Affected Fuxa server Versions

1 component(s)
Fixed Versions:
1.3.1
Product / Package Ecosystem Affected Versions Fixed Version
fuxa-server
npm/fuxa-server
npm
≥ 1.3.0
< 1.3.1
All 1 versions
1.3.0
1.3.1

References

GitHub Advisory / Wiki ADVISORY
https://github.com/frangoteam/FUXA/security/advisories/GHSA-fwcm-rqvw-j3p7
Fuxa server Source Repository REPOSITORY
https://github.com/frangoteam/FUXA/pull/2260
Security Fix Commit FIX COMMIT
https://github.com/frangoteam/FUXA/commit/78534da61a91613712b44bb63c8d7da8c5df5ca4
Fuxa server Source Repository REPOSITORY
https://github.com/frangoteam/FUXA
Fuxa server Release RELEASE
https://github.com/frangoteam/FUXA/releases/tag/v1.3.1

Frequently Asked Questions

What is CVE-2026-43946?
CVE-2026-43946 is a security vulnerability in Fuxa server involving FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue under CWE-863: Incorrect Authorization.
Which Fuxa server versions are affected?
Affected versions include releases prior to 1.3.1 across affected packages: fuxa-server.
What version fixes CVE-2026-43946?
Upgrading to 1.3.1 (or the latest patched release for your respective branch) resolves the vulnerability.
Is fuxa-server affected?
Yes, fuxa-server is affected in releases prior to 1.3.1. Upgrade your dependency to 1.3.1 or later.
What CWE is associated with CVE-2026-43946?
CVE-2026-43946 is classified under CWE-863: Incorrect Authorization (The product performs an authorization check when an actor attempts to access a resource or perform an action, but it does not correctly perform the check.).
How can I check npm dependencies for CVE-2026-43946?
Run the dependency tree command: 'npm ls fuxa-server'. 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-fwcm-rqvw-j3p7",
  "modified" : "2026-05-26T23:41:45Z",
  "published" : "2026-05-26T23:41:45Z",
  "aliases" : [ "CVE-2026-43946" ],
  "summary" : "FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue",
  "details" : "### Summary\n An authorization bypass in the /api/getTagValue endpoint allows unauthenticated access to tag values when the referenced script does not exist.\n\n  ### Details\n  The issue is caused by the combination of these code paths:\n\n  - `server/api/apikeys/verify-api-or-token.js:45` sends requests without `x-api-key` to `authJwt.verifyToken(req, res, next)`.\n  - `server/api/jwt-helper.js:46-64` creates a signed guest token when no `x-access-token` is provided:\n    `if (!token) { token = getGuestToken(); }`\n    and then populates `req.userId` / `req.userGroups` from that guest token.\n  - `server/api/command/index.js:76-105` exposes `/api/getTagValue`.\n  - `server/runtime/scripts/index.js:106-111` returns `true` when the referenced script does not exist:\n    `if (!script) { return true; }`\n\n  As a result, an unauthenticated request reaches `/api/getTagValue` as `guest`, and the authorization check is bypassed because `isAuthorisedByScriptName()` returns `true` when `sourceScriptName` is omitted or does not match a real script. The endpoint then returns arbitrary tag values by ID.\n\n  ### PoC\n\nRequests to /api/getTagValue without authentication could succeed when the authorization logic evaluated a non-existent sourceScriptName as authorized.",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N/E:P"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "fuxa-server"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "1.3.0"
      }, {
        "fixed" : "1.3.1"
      } ]
    } ],
    "versions" : [ "1.3.0" ]
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/frangoteam/FUXA/security/advisories/GHSA-fwcm-rqvw-j3p7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/frangoteam/FUXA/pull/2260"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/frangoteam/FUXA/commit/78534da61a91613712b44bb63c8d7da8c5df5ca4"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/frangoteam/FUXA"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/frangoteam/FUXA/releases/tag/v1.3.1"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-863" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-26T23:41:45Z",
    "nvd_published_at" : null
  }
}