---
id: CVE-2026-90450
title: >-
  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
summary: >-
  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…
severity: medium
cvss: 5.3
cvssVector: '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'
cwe:
  - CWE-863
vendor: CISA
product: Malcolm
affected:
  - Malcolm < v26.06.0
published: '2026-09-11'
updated: '2026-09-18'
sourceUpdated: '2026-09-18T19:40:31.053'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-90450'
references:
  - url: >-
      https://raw.githubusercontent.com/cisagov/CSAF/develop/csaf_files/OT/white/2026/icsa-26-254-01.json
    label: ics-cert@hq.dhs.gov
tags:
  - nvd
  - cve.org
epss: 0.00351
epssPercentile: 0.25931
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: partial
  timestamp: '2026-09-14T16:22:12.800064Z'
cvssSource: cna
ingestedAt: '2026-09-14T11:11:19.875Z'
---

## Overview

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

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.