CVE-2026-90447: CWE-290 Authentication bypass by spoofing in CISA Malcolm
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.
AI Analysis
Technical Summary
The vulnerability arises because a routing rule in CISA Malcolm selects between two authentication mechanisms based on a client-controlled request header rather than an immutable client property. An attacker with a shared service credential can manipulate this header to bypass the primary role-based authorization and access an alternate path with a fixed, elevated role. This enables a low-privileged authenticated user to perform actions reserved for higher-privileged roles. The affected versions are all versions before 26.06.0.
Potential Impact
An attacker who is authenticated with a shared service credential can escalate privileges by bypassing role-based authorization checks. This allows unauthorized actions that require elevated privileges, potentially compromising the integrity and security of the affected system.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Until a patch is available, restrict access to shared service credentials and monitor for misuse of client-supplied headers in requests.
CVE-2026-90447: CWE-290 Authentication bypass by spoofing in CISA Malcolm
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.
CVSS v4.0
Score 7.1high
Affected software
CISA
Malcolm
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Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
The vulnerability arises because a routing rule in CISA Malcolm selects between two authentication mechanisms based on a client-controlled request header rather than an immutable client property. An attacker with a shared service credential can manipulate this header to bypass the primary role-based authorization and access an alternate path with a fixed, elevated role. This enables a low-privileged authenticated user to perform actions reserved for higher-privileged roles. The affected versions are all versions before 26.06.0.
Potential Impact
An attacker who is authenticated with a shared service credential can escalate privileges by bypassing role-based authorization checks. This allows unauthorized actions that require elevated privileges, potentially compromising the integrity and security of the affected system.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. No official fix or patch links are provided in the available data. Until a patch is available, restrict access to shared service credentials and monitor for misuse of client-supplied headers in requests.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- icscert
- Date Reserved
- 2026-09-11T21:00:07.497Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6aa47a7955bf5e2cf581b369
Added to database: 09/11/2026, 22:02:33 UTC
Last enriched: 09/11/2026, 22:16:43 UTC
Last updated: 09/11/2026, 22:23:22 UTC
Views: 4
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