Vulnerability · Published Jul 13, 2026 · Assigned by VulnCheck

CVE-2026-57856Cockpit CMS Path Traversal via Bucket Name in Bucket File Storage API

High 8.8

In plain English

A high-severity path traversal in Cockpit CMS from Cockpit HQ. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 42% of all known vulnerabilities).

Severity (CVSS 3.1)8.8High

Exploit odds (30 days)0.5%top 58.4% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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

Affected products (as reported)

Vendor	Product	Versions
Cockpit HQ	Cockpit CMS	0 – before 2.14.0

Weakness: CWE-22 · Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

References

Product product
Patch Commit patch
https://gist.github.com/sermikr0/821c4edd3c34e98a62a50b07707785bd technical-description
https://www.vulncheck.com/advisories/cockpit-cms-missing-authorization-in-bucket-file-storage-api third-party-advisory
https://www.vulncheck.com/advisories/cockpit-cms-path-traversal-via-bucket-name-in-bucket-file-storage-api third-party-advisory