CVE-2026-120307

{
  "id": "CVE-2026-120307",
  "sourceIdentifier": "[email protected]",
  "published": "2026-11-01T13:18:01.497",
  "lastModified": "2026-11-01T13:18:01.497",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "The Beta9 worker serves the sandbox file API from outside the container. getHostPathFromContainerPath turns the tenant's container path into a worker path. If the unresolved path starts with a mount destination, including the default upload mount at /tmp/.beta9, the remainder is joined onto that mount's source with filepath.Join, which cleans parent-directory segments after the prefix check. A long enough run of those segments names any absolute path on the worker. A path that matches no mount is joined onto the container root and opened in the worker's own filesystem, so an absolute symbolic link such as /var/run pointing at /run is followed against the worker root. Upload, download, stat, list, find-in-files, replace-in-files, and delete-file all call this helper. A tenant with a workspace token and one running sandbox can read, write, list, and delete files on the hosting worker as root, including files of other tenants on that machine. A read-only proof downloaded the worker pod's Kubernetes service account token through the file API for a path that did not exist inside the sandbox. In the shipped remote-node manifests that service account is bound to cluster-admin. Fixed in worker 0.1.756: sandbox file operations and workspace sync open paths with os.OpenRoot, so parent-directory and symlink lookups stay inside the container root or the mount source."
    }
  ],
  "affected": [
    {
      "source": "[email protected]",
      "affectedData": [
        {
          "vendor": "beam-cloud",
          "product": "Beta9 worker",
          "defaultStatus": "unaffected",
          "collectionURL": "https://github.com/beam-cloud/beta9/releases",
          "packageName": "github.com/beam-cloud/beta9",
          "programFiles": [
            "pkg/worker/container_server.go",
            "pkg/worker/lifecycle.go",
            "pkg/types/worker.go"
          ],
          "repo": "git://github.com/beam-cloud/beta9",
          "versions": [
            {
              "version": "0",
              "lessThan": "0.1.756",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "[email protected]",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "CHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 3.1,
        "impactScore": 6.0
      }
    ]
  },
  "weaknesses": [
    {
      "source": "[email protected]",
      "type": "Primary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-22"
        },
        {
          "lang": "en",
          "value": "CWE-23"
        },
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://github.com/beam-cloud/beta9",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/beam-cloud/beta9/commit/a28bf12cf0007c792a25d8ed282b4e8bf6f30393",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/beam-cloud/beta9/pull/1897",
      "source": "[email protected]"
    },
    {
      "url": "https://github.com/beam-cloud/beta9/releases/tag/worker-0.1.756",
      "source": "[email protected]"
    }
  ]
}