GHSA-FWCM-RQVW-J3P7

Vulnerability from github – Published: 2026-05-26 23:41 – Updated: 2026-05-26 23:41
VLAI
Summary
FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue
Details

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.

Severity
7.7 (High)
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
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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "fuxa-server"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "1.3.0"
            },
            {
              "fixed": "1.3.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "1.3.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2026-43946"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-863"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-26T23:41:45Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "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.",
  "id": "GHSA-fwcm-rqvw-j3p7",
  "modified": "2026-05-26T23:41:45Z",
  "published": "2026-05-26T23:41:45Z",
  "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"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "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",
      "type": "CVSS_V4"
    }
  ],
  "summary": "FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue"
}



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