The filestore backend in pkg/object/file.go, used for file:// stores and as a common juicefs sync destination, derived every operation's target from path(key), which returned either filepath.Join(d.root, key) or filepath.Clean(d.root + key) with no check that the result stayed beneath the root. Put, Get, Head, Delete, Chmod, Chown, Symlink and Readlink all consumed that value directly. Object keys enumerated from a source object store during a sync are not constrained the way local filesystem names are, so a key containing traversal segments causes juicefs to write attacker-supplied content to a path outside the intended local destination, and no error is returned. An operator syncing from a bucket whose contents they do not fully control, such as a shared or public bucket or one an attacker can write to, is therefore exposed to a file write at an attacker-influenced location. The fix changes path() to return an error and rejects any key whose resolved path escapes the root.
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Fixes
Solution
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Workaround
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References
History
Fri, 21 Aug 2026 11:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | The filestore backend in pkg/object/file.go, used for file:// stores and as a common juicefs sync destination, derived every operation's target from path(key), which returned either filepath.Join(d.root, key) or filepath.Clean(d.root + key) with no check that the result stayed beneath the root. Put, Get, Head, Delete, Chmod, Chown, Symlink and Readlink all consumed that value directly. Object keys enumerated from a source object store during a sync are not constrained the way local filesystem names are, so a key containing traversal segments causes juicefs to write attacker-supplied content to a path outside the intended local destination, and no error is returned. An operator syncing from a bucket whose contents they do not fully control, such as a shared or public bucket or one an attacker can write to, is therefore exposed to a file write at an attacker-influenced location. The fix changes path() to return an error and rejects any key whose resolved path escapes the root. | |
| Title | JuiceFS Local Filestore Backend Joins Object Keys onto the Storage Root Without a Containment Check, Allowing Writes Outside the Configured Directory | |
| First Time appeared |
Juicedata
Juicedata juicefs |
|
| Weaknesses | CWE-22 | |
| CPEs | cpe:2.3:a:juicedata:juicefs:*:*:*:*:*:*:*:* | |
| Vendors & Products |
Juicedata
Juicedata juicefs |
|
| References |
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|
| Metrics |
cvssV3_1
|
Projects
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Status: PUBLISHED
Assigner: VulnCheck
Published:
Updated: 2026-08-21T11:05:13.650Z
Reserved: 2026-08-21T10:30:49.467Z
Link: CVE-2026-77763
No data.
Status : Received
Published: 2026-08-21T11:17:06.937
Modified: 2026-08-21T11:17:06.937
Link: CVE-2026-77763
No data.
OpenCVE Enrichment
Updated: 2026-08-21T12:45:04Z
Weaknesses