GHSA-fwcm-rqvw-j3p7 CVE-2026-43946

FUXA has an unauthenticated arbitrary tag value disclosure via /api/getTagValue

High npm

Severity: 0.0 / 10; High · CVSS 4.0
Exploit chance (EPSS): 0.57%; Chance of exploitation in the next 30 days. Higher than 47.02% of scored vulnerabilities.
Known exploited: No; Not in CISA's catalog
Weakness: CWE-863 Incorrect Authorization
Fix: 1.3.1; Upgrade fuxa-server to this version or later

Description

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.

Affected versions

npm

Package	Vulnerable	Fixed in
fuxa-server	`>= 1.3.0, < 1.3.1`	`1.3.1`

How to fix

Move to the fixed version or later with your package manager, update the lockfile, and run your tests. If the package only arrives through another dependency, upgrade that dependency first. If none of its releases pulls a fixed version yet, force the version with your package manager's override.

fuxa-server npm → `1.3.1`

npm

npm install fuxa-server@1.3.1

yarn

yarn add fuxa-server@1.3.1

pnpm

pnpm add fuxa-server@1.3.1

Severity breakdown

CVSS 4.0 0.0

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

Attack vector: Network
Attack complexity: Low
Attack requirements: None
Privileges required: None
User interaction: None
Confidentiality (vulnerable system): High
Integrity (vulnerable system): None
Availability (vulnerable system): None
Confidentiality (subsequent systems): None
Integrity (subsequent systems): None
Availability (subsequent systems): None
Exploit maturity: Proof of concept

Weakness

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 to prevent it

Architecture and Design: Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) [REF-229] to enforce the roles at the appropriate boundaries. Note that this approach may not protect against horizontal authorization, i.e., it will not protect a user from attacking others with the same role.
Architecture and Design: Ensure that access control checks are performed related to the business logic. These checks may be different than the access control checks that are applied to more generic resources such as files, connections, processes, memory, and database records. For example, a database may restrict access for medical records to a specific database user, but each record might only be intended to be accessible to the patient and the patient's doctor [REF-7].
Architecture and Design: Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid. For example, consider using authorization frameworks such as the JAAS Authorization Framework [REF-233] and the OWASP ESAPI Access Control feature [REF-45].
Architecture and Design: For web applications, make sure that the access control mechanism is enforced correctly at the server side on every page. Users should not be able to access any unauthorized functionality or information by simply requesting direct access to that page. One way to do this is to ensure that all pages containing sensitive information are not cached, and that all such pages restrict access to requests that are accompanied by an active and authenticated session token associated with a user who has the required permissions to access that page.
System Configuration, Installation: Use the access control capabilities of your operating system and server environment and define your access control lists accordingly. Use a "default deny" policy when defining these ACLs.

References

Packages

github.com/frangoteam/FUXA

Timeline

May 26, 2026 Published
Oct 24, 2026 Last updated by the source
Oct 31, 2026 Latest EPSS score

Advisory	Severity	Why it's related
GHSA-8ghr-w65f-j3qr FUXA's scheduler API missing admin check enables operator-to-admin escalation via scheduled device actions	Medium	Also affects fuxa-server
GHSA-h9fj-c2qr-76g2 FUXA has SQL Injection in its TDengine DAQ connector via backslash bypass of escapeTdString	Medium	Also affects fuxa-server
GHSA-w86f-rf9w-h3x6 FUXA: Unauthenticated SSRF via Socket.IO DEVICE_WEBAPI_REQUEST and DEVICE_PROPERTY with response reading	High	Also affects fuxa-server
GHSA-r9g5-7q8j-958c FUXA provides guest and invalid-token access to protected read APIs in secure mode	Medium	Also affects fuxa-server
GHSA-q3w6-q3hc-c5x6 FUXA's Unauthenticated Project Data Disclosure Exposes Server-Side Scripts and Device Configurations	High	Also affects fuxa-server
GHSA-rg3m-cfq7-g6h6 FUXA Vulnerable to Unauthenticated Remote Code Execution via Script Test Mode Authorization Bypass	High	Also affects fuxa-server
GHSA-68m5-5w2h-h837 FUXA Affected by a Path Traversal Sanitization Bypass	High	Also affects fuxa-server
GHSA-c869-jx4c-q5fc FUXA Unauthenticated Remote Arbitrary Scheduler Write	Critical	Also affects fuxa-server

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