Ceph Monitor subscription handler improperly authorizes config-key store reads, exposing cluster secrets to read-only users

{
  "id": "f94db7f002df40c8040941438ea6af516eec6a17fd474f60f6f48328edb96c9c",
  "url": "https://osv.dev/vulnerability/CVE-2026-50152",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Ceph Monitor subscription handler improperly authorizes config-key store reads, exposing cluster secrets to read-only users",
    "summary": "Ceph is an open-source distributed storage platform providing object, block, and file storage. In versions prior to 20.2.4 and 19.2.6, the Monitor subscription handler fails to properly authorize access to the configuration-key store, allowing any CephX user with only `mon allow r` capabilities to read the entire store by sending a single crafted MMonSubscribe message. The config-key store holds sensitive secrets including OSD LUKS disk-encryption passphrases and, on cephadm-managed clusters, the SSH private key that cephadm uses to reach every host in the cluster. Because that key grants root on every node under the default cephadm configuration, a low-privileged read-only account can escalate to full cluster and host compromise. This issue is fixed in versions 20.2.4 and 19.2.6",
    "evidence": "osv:CVE-2026-50152",
    "products": [],
    "severity": "critical",
    "structured": {
      "id": "CVE-2026-50152",
      "aliases": [
        "BIT-ceph-2026-50152",
        "CVE-2026-50152",
        "GHSA-rg9p-5xcp-wm8h"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/ceph/ceph",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1680e466aab77cdf9ba07394bea664106580b32b"
                },
                {
                  "fixed": "f9fd95b4335bad6a26d7a74468f55d269e8dbef4"
                },
                {
                  "introduced": "3d911bce7d6557aa2d1826543a4a4e88981639da"
                },
                {
                  "fixed": "7f793731f1b39eb4f465e960113d2363c311b964"
                },
                {
                  "fixed": "d971bb2b6199f70b1708a20a63fa944ee7a94727"
                },
                {
                  "fixed": "f2840d2fd338ab5de2865f0f78684bbf7b888c84"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "19.0.0"
                      },
                      {
                        "fixed": "19.2.6"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "20.0.0"
                      },
                      {
                        "fixed": "20.2.4"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "d971bb2b6199f70b1708a20a63fa944ee7a94727"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "f2840d2fd338ab5de2865f0f78684bbf7b888c84"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v20.2.3",
            "v19.2.5",
            "v20.2.2-pre.ibm",
            "v20.2.1-pre.ibm.0",
            "v20.1.0-pre.ibm.2",
            "v20.1.0-pre.ibm.1",
            "v20.0.0-pre.ibm",
            "v19.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50152.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:23.973629116Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50152.json",
        "https://github.com/ceph/ceph/security/advisories/GHSA-rg9p-5xcp-wm8h",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50152",
        "https://github.com/ceph/ceph/commit/d971bb2b6199f70b1708a20a63fa944ee7a94727",
        "https://github.com/ceph/ceph/commit/f2840d2fd338ab5de2865f0f78684bbf7b888c84"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-285"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50152.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-50152",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 490535,
  "published_at": "2026-08-27T20:53:42.353+00:00"
}