CVE-2026-50152

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

Published Aug 27, 2026 CVSS 3.1 · 9.1 Critical EPSS < 1% KEV · Not listed
Description
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

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

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History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
Description A flaw was found in the MON subscription handler of Ceph, a distributed storage system. The handler does not properly authorize access to the config-key store when processing MMonSubscribe messages. Any CephX user holding mon allow r capabilities can read the entire config-key store, which contains sensitive operational secrets including OSD LUKS disk encryption passphrases and, on clusters managed by cephadm, the SSH private key used to administer every host. Exposure of these secrets can lead to full host-level root access and compromise of encrypted data at rest. 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
Title ceph: ceph: MON subscription handler exposes config-key store to low-privilege CephX users Ceph Monitor subscription handler improperly authorizes config-key store reads, exposing cluster secrets to read-only users
Weaknesses CWE-285
References
Metrics cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L'}

cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L'}

Type Values Removed Values Added
First Time appeared Ceph
Ceph ceph
Vendors & Products Ceph
Ceph ceph
Type Values Removed Values Added
Description A flaw was found in the MON subscription handler of Ceph, a distributed storage system. The handler does not properly authorize access to the config-key store when processing MMonSubscribe messages. Any CephX user holding mon allow r capabilities can read the entire config-key store, which contains sensitive operational secrets including OSD LUKS disk encryption passphrases and, on clusters managed by cephadm, the SSH private key used to administer every host. Exposure of these secrets can lead to full host-level root access and compromise of encrypted data at rest.
Title ceph: ceph: MON subscription handler exposes config-key store to low-privilege CephX users
Weaknesses CWE-862
References
Metrics threat_severity

None

cvssV3_1

{'score': 8.2, 'vector': 'CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L'}

threat_severity

Important

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Sep 1, 2026, 2:48 PM
Reserved
Jun 3, 2026, 8:54 PM
Status
Awaiting Analysis
Published
Aug 28, 2026, 12:18 AM
Modified
Sep 8, 2026, 9:11 PM
Severity
Important
Public date
Aug 19, 2026, 5:57 PM