Cockpit CMS Path Traversal via Bucket Name in Bucket File Storage API

{
  "id": "c796ce5fb260bb85f7788edbc8bf7afbc8b679192cbe46b6a8868df686e7c1fb",
  "url": "https://osv.dev/vulnerability/CVE-2026-57856",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Cockpit CMS Path Traversal via Bucket Name in Bucket File Storage API",
    "summary": "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",
    "evidence": "osv:CVE-2026-57856",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-57856",
      "aliases": [
        "CVE-2026-57856"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/cockpit-hq/cockpit",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "dde2d1d74f5f4e11de42a298918ea8c9684f932c"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "2.14.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "fixed": "dde2d1d74f5f4e11de42a298918ea8c9684f932c"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "2.13.5",
            "2.13.4",
            "2.13.3",
            "2.13.2",
            "2.13.1",
            "2.13.0",
            "2.12.1",
            "2.12.0",
            "2.11.4",
            "2.11.3",
            "2.11.2",
            "2.11.1",
            "2.11.0",
            "2.10.3",
            "2.10.2",
            "2.10.1",
            "2.10.0",
            "2.9.4",
            "2.9.3",
            "2.9.2",
            "2.9.1",
            "2.9.0",
            "2.8.6",
            "2.8.5",
            "2.8.4",
            "2.8.3",
            "2.8.2",
            "2.8.1",
            "2.8.0",
            "2.7.2",
            "2.7.1",
            "2.7.0",
            "2.6.3",
            "2.6.2",
            "2.6.1",
            "2.6.0",
            "2.5.2",
            "2.5.1",
            "2.5.0",
            "2.4.1",
            "2.4.0",
            "2.3.9",
            "2.3.8",
            "2.3.7",
            "2.3.6",
            "2.3.5",
            "2.3.4",
            "2.3.3",
            "2.3.2",
            "2.3.1",
            "2.3.0",
            "2.2.2",
            "2.2.1",
            "2.2.0",
            "2.1.2",
            "2.1.1",
            "2.1.0",
            "2.0.2",
            "2.0.1",
            "2.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-57856.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:29.191534657Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57856.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-57856",
        "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://github.com/Cockpit-HQ/Cockpit/commit/dde2d1d74f5f4e11de42a298918ea8c9684f932c",
        "https://github.com/cockpit-hq/cockpit",
        "https://gist.github.com/sermikr0/821c4edd3c34e98a62a50b07707785bd"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-22"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/57xxx/CVE-2026-57856.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-57856",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 495974,
  "published_at": "2026-07-13T22:41:23.183+00:00"
}