CVE-2026-57856
Cockpit CMS contains a path traversal vulnerability in the Bucket file storage API (/system/buckets/api). The api() method in modules/System/Controller/Buckets.php sanitizes the bucket name with preg_replace('/[^a-zA-Z0-9-_\\.]/','', $bucket), which permits '..' and '../' sequences. The sanitized value is interpolated into a Flysystem path as uploads://buckets/{bucket}. Flysystem's WhitespacePathNormalizer resolves 'buckets/..' to the empty string (the uploads storage root) without raising PathTraversalDetected because the '..' has a preceding component to consume. An authenticated low-privileged user can send a crafted request with a '../' bucket name to list, upload, and delete files across all buckets, including those belonging to other users or roles
What this means
- Exposure
- Exploitable remotely over the network, with an ordinary user account and with no action from the victim.
- Impact
- An attacker can read sensitive data, modify or destroy data and take the service offline.
- Weakness
- An attacker-supplied file path is not confined, letting them read or write outside the intended folder.
- Likelihood
- Its EPSS score stays low: nothing points to imminent exploitation, which is no reason to leave it unpatched.
What to doFold into the next patch cycle.
Read automatically from the CVSS vector, the weakness type (CWE) and the EPSS score. The technical description above remains the one published by NIST.