A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.

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Advisories

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Fixes

Solution

The latest version of Malcolm (September 2026 or later) fixes these vulnerabilities. Affected users are encouraged to update their instance of Malcolm to the latest version.


Workaround

No workaround given by the vendor.

History

Fri, 11 Sep 2026 23:45:00 +0000

Type Values Removed Values Added
Description A routing rule selects between two different authentication mechanisms for the same downstream service based on the value of a client-supplied request header, rather than on any property the client cannot control. An authenticated user in possession of a shared service credential can set this header to route around the primary role-based authorization check and reach the alternate path's fixed, elevated role instead. This allows a low-privileged authenticated attacker who knows the shared credential to perform actions reserved for a higher-privileged role.
Weaknesses CWE-290
References
Metrics cvssV4_0

{'score': 7.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N'}


Projects

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cve-icon MITRE

Status: PUBLISHED

Assigner: icscert

Published:

Updated: 2026-09-11T21:48:51.996Z

Reserved: 2026-09-11T21:00:07.497Z

Link: CVE-2026-90447

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Received

Published: 2026-09-11T22:16:46.797

Modified: 2026-09-11T22:16:46.797

Link: CVE-2026-90447

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses