CVE-2026-77763 Path traversal in juicefs
Attacker-controlled object keys during sync can write files outside the configured storage root, allowing arbitrary file modification.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2026-77763?
CVE-2026-77763 is a high-severity path traversal vulnerability in juicedata juicefs, published on 21 Aug 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official 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.
Weakness: CWE-22
Which versions are affected by CVE-2026-77763?
How do I fix CVE-2026-77763?
No fix has been published for CVE-2026-77763 yet. Limit exposure of the affected software until one is available.
Upgrade, and resolve every user-supplied path against an allowed base folder before opening it. More about Path traversal.
Is CVE-2026-77763 being exploited?
There is no known exploitation of CVE-2026-77763 in the wild and no public exploit code.
Sources
Also known as GHSA-2pgv-c2r7-f43r.