Arbitrary file write via S3 key traversal
Published Aug 13, 2026 · Updated Aug 14, 2026
Path traversal in Budibase Server before 3.40.0 allows remote authenticated users to write arbitrary content during workspace export. The retrieveDirectory function splits an S3 object key containing preserved .. segments and passes them to path.join without checking that the resolved destination remains inside the export directory. Builder access permits a crafted upload and later export, allowing writes only to paths writable by the Budibase process.
Summary
What happened
Path traversal in Budibase Server before 3.40.0 allows remote authenticated users to write arbitrary content during workspace export. The retrieveDirectory function splits an S3 object key containing preserved .. segments and passes them to path.join without checking that the resolved destination remains inside the export directory. Builder access permits a crafted upload and later export, allowing writes only to paths writable by the Budibase process.
The record
- CVE
- CVE-2026-72850
- Published
- Aug 13, 2026
- Updated
- Aug 14, 2026
- Vendor
- Budibase
- Product
- Budibase Server
- Classifications
- CWE-1188, CWE-73, CWE-22, T1105
- Attack vector
- network
- Privileges
- authenticated
Timeline
How it unfolded
- Aug 13, 2026CVE publishedPublication date reported by the CVE source.
- Aug 14, 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 <3.40.0
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
- Vendor advisory controlled-runtime path-traversal proof of conceptproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
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Your stack
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