CVE-2026-82042

CRITICAL 9.8

UTMStack < 11.2.16 Authentication Bypass via InternalApiKeyFilter

CVSS Score

9.8

EPSS Score

0.0%

EPSS Percentile

0th

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.

CWE	CWE-306
Vendor	utmstack
Product	utmstack
Published	Oct 2, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

UTMStack / UTMStack

0 < 11.2.16

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/UTMStack/UTMStack/releases/tag/v11.2.16 github.com: https://github.com/utmstack/UTMStack/commit/4e7a727c3b8d8e2ad020d3b4f982a6d085dbecdd vulncheck.com: https://www.vulncheck.com/advisories/utmstack-authentication-bypass-via-internalapikeyfilter

Credits

Adam Nurudini (QwesiRED) VulnCheck