Open redirect via unvalidated upload Referer
Published Sep 11, 2026 · Updated Sep 11, 2026
Open redirect in Malcolm before 26.06.0 allows context-dependent attackers to redirect authenticated users after a crafted upload request. The submit.php file-upload handler copies the request's Referer header into its HTTP Location response without checking that the destination shares Malcolm's origin. Exploitation requires an authenticated victim to submit an attacker-crafted upload request, after which the browser is sent to an attacker-controlled external site; no direct data modification or service interruption is reported.
Summary
What happened
Open redirect in Malcolm before 26.06.0 allows context-dependent attackers to redirect authenticated users after a crafted upload request. The submit.php file-upload handler copies the request's Referer header into its HTTP Location response without checking that the destination shares Malcolm's origin. Exploitation requires an authenticated victim to submit an attacker-crafted upload request, after which the browser is sent to an attacker-controlled external site; no direct data modification or service interruption is reported.
The record
- CVE
- CVE-2026-90453
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- Cybersecurity and Infrastructure Security Agency (CISA)
- Product
- Malcolm
- Classifications
- Unavailable
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Sep 11, 2026CVE publishedPublication date reported by the CVE source.
- Sep 11, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <v26.06.0
What conditions does exploitation require?
What is affected?
Published CVSS scores
No CVSS assessment is available in this record.
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Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
No sourced classifications are available.
Public exploit references
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Technologies
Your stack
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Your stack
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