CVE-2026-90450

Incorrect Authorization in Malcolm

Published Sep 11, 2026 CVSS 4.0 · 5.3 Medium EPSS < 1% KEV · Not listed
Description
The application's role-authorization lookup defaults to granting access when a request handler's name is not present in its table of role requirements, rather than defaulting to deny. Any request handler that is not explicitly registered in this table is reachable by any authenticated user regardless of their assigned role, and any newly added handler is fail-open by default until explicitly added to the table.

Remediation

Vendor 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.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Title Incorrect Authorization in Malcolm
References
Metrics cvssV3_1

{'score': 4.3, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N'}

Type Values Removed Values Added
Title Fail‑Open Role Authorization Leading to Privilege Escalation in Malcolm
Type Values Removed Values Added
Title Fail‑Open Role Authorization Leading to Privilege Escalation in Malcolm
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Title Fail-Open Role Authorization Enables Unauthorized Access in Malcolm
Type Values Removed Values Added
Title Fail-Open Role Authorization Enables Unauthorized Access in Malcolm
Type Values Removed Values Added
First Time appeared Cisagov
Cisagov malcolm
Vendors & Products Cisagov
Cisagov malcolm
Type Values Removed Values Added
Title Privilege Escalation via Fail‑Open Role Authorization in Malcolm
Type Values Removed Values Added
Title Privilege Escalation via Fail‑Open Role Authorization in Malcolm
Type Values Removed Values Added
Title Fail‑Open Role Authorization Leading to Privilege Escalation in Malcolm
Type Values Removed Values Added
Title Fail‑Open Role Authorization Leading to Privilege Escalation in Malcolm
Type Values Removed Values Added
Description The application's role-authorization lookup defaults to granting access when a request handler's name is not present in its table of role requirements, rather than defaulting to deny. Any request handler that is not explicitly registered in this table is reachable by any authenticated user regardless of their assigned role, and any newly added handler is fail-open by default until explicitly added to the table.
Weaknesses CWE-863
References
Metrics cvssV4_0

{'score': 5.3, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
icscert
Published
Updated
Oct 2, 2026, 9:03 PM
Reserved
Sep 11, 2026, 9:00 PM
Status
Awaiting Analysis
Published
Sep 11, 2026, 10:16 PM
Modified
Oct 2, 2026, 10:16 PM