What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 8.8 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.5% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-07-13 · updated 2026-10-24
• Weakness: CWE-22

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

• Cockpit HQ Cockpit CMS: all versions

References

• https://gist.github.com/sermikr0/821c4edd3c34e98a62a50b07707785bd
• https://github.com/Cockpit-HQ/Cockpit/commit/dde2d1d74f5f4e11de42a298918ea8c9684f932c
• https://github.com/cockpit-hq/cockpit
• https://www.vulncheck.com/advisories/cockpit-cms-missing-authorization-in-bucket-file-storage-api
• https://www.vulncheck.com/advisories/cockpit-cms-path-traversal-via-bucket-name-in-bucket-file-storage-api
• https://gist.github.com/sermikr0/821c4edd3c34e98a62a50b07707785bd

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