Arbitrary file write via filename header traversal
Published Sep 13, 2026 · Updated Sep 13, 2026
Path traversal in Rustypaste before 0.18.1 allows remote attackers to write files outside the upload directory via a filename header. Destination validation occurs before the optional header replaces the checked filename, so traversal sequences bypass the directory-escape check. Without configured authentication, any remote client able to upload content can write to filesystem locations accessible to the service account.
Summary
What happened
Path traversal in Rustypaste before 0.18.1 allows remote attackers to write files outside the upload directory via a filename header. Destination validation occurs before the optional header replaces the checked filename, so traversal sequences bypass the directory-escape check. Without configured authentication, any remote client able to upload content can write to filesystem locations accessible to the service account.
The record
- CVE
- CVE-2026-90774
- Published
- Sep 13, 2026
- Updated
- Sep 13, 2026
- Vendor
- Orhun Parmaksız
- Product
- Rustypaste
- Classifications
- T1190
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Sep 13, 2026CVE publishedPublication date reported by the CVE source.
- Sep 13, 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 <0.18.1
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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