CVE-2026-77763: Path Traversal (CVSS 6.5)

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.

Is your site exposed to CVE-2026-77763?

Run a free security scan — no signup, results in seconds.

CVSS v3.1 Score

6.5

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N

EPSS — Exploit Prediction

0.0033

Probability of exploitation

0.26%

Percentile rank

EPSS estimates the probability that this vulnerability will be exploited in the wild within the next 30 days. A higher score means more likely to be exploited.

Weakness Type (CWE)

CWE-22 Path Traversal

References

Other References

https://github.com/juicedata/juicefs https://github.com/juicedata/juicefs/blob/v1.4.1/pkg/object/file.go https://github.com/juicedata/juicefs/commit/0bcd70b3d13088d38127d6fb5750c91be7c4ec16 https://github.com/juicedata/juicefs/issues/7401 https://github.com/juicedata/juicefs/pull/7425 https://www.vulncheck.com/advisories/juicefs-local-filestore-backend-joins-object-keys-onto-the-storage-root-without-a-containment-check-allowing-writes-outside-the-configured-directory

Frequently Asked Questions

What is CVE-2026-77763? +

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. It has a CVSS v3.1 base score of 6.5 (MEDIUM).

How severe is CVE-2026-77763? +

CVE-2026-77763 has a CVSS v3.1 score of 6.5 out of 10, rated MEDIUM. This is a medium-severity vulnerability that should be remediated as part of regular maintenance. The EPSS score is 0.0033, placing it in the 0th percentile for exploitation probability.

How do I check if I'm vulnerable to CVE-2026-77763? +

You can use Secably's free Website Scanner to check your website for known vulnerabilities. For infrastructure scanning, use the Port Scanner to identify exposed services that may be affected. Check the vendor advisories linked above for specific patch and version information.

Related Vulnerabilities

CVE-2026-65886

Joomla Extension - balbooa.com - Unauthenticated arbitrary file read in Gridbox < 2.20.2 - The photo viewer allows unauthenticated attackers …

CVE-2024-56514

Karmada is a Kubernetes management system that allows users to run cloud-native applications across multiple Kubernetes clusters and clouds. Prior …

CVE-2026-43965

Path traversal vulnerability in Gleam's dependency management allows arbitrary directory deletion via malicious build/packages/packages.toml content. Package keys read from build/packages/packages.toml …

CVE-2026-40605

Tautulli is a Python based monitoring and tracking tool for Plex Media Server. Prior to version 2.17.1, a path traversal …

CVE-2026-41140

Poetry is a dependency manager for Python. Prior to 2.3.4, the extractall() function in src/poetry/utils/helpers.py:410-426 extracts sdist tarballs without path …

CVE-2026-7766

Kenik Camera management Panel is vulnerable to Path Traversal vulnerability. An unauthenticated attacker can send GET request with arbitrary file …

CVE-2026-77763