---
id: CVE-2026-82042
title: >-
  UTMStack before 11.2.16 contains an authentication bypass vulnerability that
  allows remote attackers to gain full administrative API access by presenting a
  valid Utm-Internal-Key header matching the INTERNAL_KEY environment variable
  valu…
summary: >-
  UTMStack before 11.2.16 contains an authentication bypass vulnerability that
  allows remote attackers to gain full administrative API access by presenting a
  valid Utm-Internal-Key header matching the INTERNAL_KEY environment variable
  valu…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cwe:
  - CWE-306
vendor: UTMStack
product: UTMStack
affected:
  - UTMStack < 11.2.16
published: '2026-10-02'
updated: '2026-10-02'
sourceUpdated: '2026-10-02T21:16:56.643'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-82042'
references:
  - url: 'https://github.com/UTMStack/UTMStack/releases/tag/v11.2.16'
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/utmstack/UTMStack/commit/4e7a727c3b8d8e2ad020d3b4f982a6d085dbecdd
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/utmstack-authentication-bypass-via-internalapikeyfilter
    label: disclosure@vulncheck.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-10-02T22:33:09.847Z'
---

## Overview

UTMStack before 11.2.16 contains an authentication bypass vulnerability that allows remote attackers to gain full administrative API access by presenting a valid Utm-Internal-Key header matching the INTERNAL_KEY environment variable value, which the InternalApiKeyFilter accepts for any endpoint without path restriction, constant-time comparison, rate limiting, or audit logging. Attackers who obtain the key value can authenticate without a user account or JWT to create accounts, manage users, exfiltrate data, and modify security rules.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.