Authenticated arbitrary file writes via archive traversal
Published Sep 11, 2026 · Updated Sep 11, 2026
Path traversal in Malcolm before 26.06.0 allows remote authenticated users to write files outside the upload extraction directory. The upload path passes unvalidated archive member names through pyunpack and patool to system extractors, which honor traversal sequences. Upload access and a crafted archive are required; resulting writes use filebeat process privileges and can inject stored records or alter configuration.
Summary
What happened
Path traversal in Malcolm before 26.06.0 allows remote authenticated users to write files outside the upload extraction directory. The upload path passes unvalidated archive member names through pyunpack and patool to system extractors, which honor traversal sequences. Upload access and a crafted archive are required; resulting writes use filebeat process privileges and can inject stored records or alter configuration.
The record
- CVE
- CVE-2026-90445
- Published
- Sep 11, 2026
- Updated
- Sep 11, 2026
- Vendor
- Cybersecurity and Infrastructure Security Agency (CISA)
- Product
- Malcolm
- Classifications
- T1190
- 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
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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