UTMStack up to 11.2.15 InternalApiKeyFilter improper authentication

Summaryinfo

A vulnerability has been found in UTMStack up to 11.2.15 and classified as very critical. Affected by this issue is some unknown functionality of the component InternalApiKeyFilter. This manipulation causes improper authentication. This vulnerability is tracked as CVE-2026-82042. The attack is possible to be carried out remotely. No exploit exists. The affected component should be upgraded.

Detailsinfo

A vulnerability classified as very critical was found in UTMStack up to 11.2.15. Affected by this vulnerability is an unknown part of the component InternalApiKeyFilter. The manipulation with an unknown input leads to a improper authentication vulnerability. The CWE definition for the vulnerability is CWE-287. When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at github.com. This vulnerability is known as CVE-2026-82042 since 08/27/2026. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. The technical details are unknown and an exploit is not publicly available. The pricing for an exploit might be around USD $0-$5k at the moment (estimation calculated on 10/02/2026).

Upgrading to version 11.2.16 eliminates this vulnerability.

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Productinfo

Name

• UTMStack

Version

• 11.2.0
• 11.2.1
• 11.2.2
• 11.2.3
• 11.2.4
• 11.2.5
• 11.2.6
• 11.2.7
• 11.2.8
• 11.2.9
• 11.2.10
• 11.2.11
• 11.2.12
• 11.2.13
• 11.2.14
• 11.2.15

Website

• Product: https://github.com/UTMStack/UTMStack/

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