Authenticated file disclosure via reserved upload fields
Published Aug 21, 2026 · Updated Aug 21, 2026
Path manipulation in OctoPrint before 1.11.8 and 2.0.0rc1 through 2.0.0rc2 allows remote authenticated users to disclose host files. The custom Tornado upload handler and Flask with Werkzeug interpret request parameters differently, so reserved internal fields supplied through query parameters or parser differentials make arbitrary readable host files appear to be temporary uploads. FILE_UPLOAD permission is required; successful exploitation moves a selected file into a downloadable upload directory and can remove runtime files that affect a later restart.
Summary
What happened
Path manipulation in OctoPrint before 1.11.8 and 2.0.0rc1 through 2.0.0rc2 allows remote authenticated users to disclose host files. The custom Tornado upload handler and Flask with Werkzeug interpret request parameters differently, so reserved internal fields supplied through query parameters or parser differentials make arbitrary readable host files appear to be temporary uploads. FILE_UPLOAD permission is required; successful exploitation moves a selected file into a downloadable upload directory and can remove runtime files that affect a later restart.
The record
- CVE
- CVE-2026-54134
- Published
- Aug 21, 2026
- Updated
- Aug 21, 2026
- Vendor
- OctoPrint
- Product
- OctoPrint
- Classifications
- CWE-436, CWE-73, CAPEC-76, T1005
- Attack vector
- adjacent
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 21, 2026CVE publishedPublication date reported by the CVE source.
- Aug 21, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
Compare your product and version with the public record. A matching version still requires validation against your environment.
Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=< 1.11.8
- Affected versionversion=>= 2.0.0rc1, < 2.0.0rc3
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
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
Public exploit references
No public exploit references are available in this record.
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
Check the software in your environment
Book a demo to see how Hinoki identifies affected software and validates exploitability in your environment.
Book a demo