CVE-2026-90453

Open Redirect in Malcolm

Published Sep 11, 2026 CVSS 4.0 · 5.1 Medium EPSS < 1% KEV · Not listed
Description
A file-upload handler redirects the authenticated client's browser to a URL taken directly from that same request's Referer header, without validating it against the application's own origin. This allows an authenticated attacker to craft a request that causes another user's browser to be redirected to an arbitrary external destination after completing an upload.

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 Open Redirect via Unvalidated Referer in Malcolm File‑Upload Open Redirect in Malcolm
References
Metrics cvssV3_1

{'score': 3.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:L/A:N'}

Type Values Removed Values Added
Title Open Redirect via Unvalidated Referer in Malcolm File‑Upload
Type Values Removed Values Added
Title Authenticated Open Redirect via File Upload Referer Header
Type Values Removed Values Added
Title Authenticated Open Redirect via File Upload Referer Header
Type Values Removed Values Added
Metrics ssvc

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

Type Values Removed Values Added
Title Authenticated Open Redirect via Constructed Referer Header
Type Values Removed Values Added
Title Authenticated Open Redirect via Constructed Referer Header
Type Values Removed Values Added
First Time appeared Cisagov
Cisagov malcolm
Vendors & Products Cisagov
Cisagov malcolm
Type Values Removed Values Added
Title Open Redirect via Referer Header after File Upload in Malcolm
Type Values Removed Values Added
Title Open Redirect via Referer Header after File Upload in Malcolm
Type Values Removed Values Added
Title Authenticated Open Redirect in Malcolm File‑Upload Handler
Type Values Removed Values Added
Title Authenticated Open Redirect in Malcolm File‑Upload Handler
Type Values Removed Values Added
Description A file-upload handler redirects the authenticated client's browser to a URL taken directly from that same request's Referer header, without validating it against the application's own origin. This allows an authenticated attacker to craft a request that causes another user's browser to be redirected to an arbitrary external destination after completing an upload.
Weaknesses CWE-601
References
Metrics cvssV4_0

{'score': 5.1, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:P/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
icscert
Published
Updated
Oct 2, 2026, 8:56 PM
Reserved
Sep 11, 2026, 9:00 PM
Status
Awaiting Analysis
Published
Sep 11, 2026, 10:16 PM
Modified
Oct 2, 2026, 9:16 PM