Ceph is an open-source distributed storage platform providing object, block, and file storage

Overview

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

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.

Vendor advisories

• RHSA-2026:79243 · Red Hat · fixed in: Red Hat Ceph Storage 8.1 · released 2026-10-08 · advisory
• Red Hat VEX · Important · affected: Red Hat Ceph Storage 4, Red Hat Ceph Storage 5, Red Hat Ceph Storage 6, Red Hat Ceph Storage 7, Red Hat Ceph Storage 8, Red Hat Ceph Storage 9 · no fix planned: Red Hat Ceph Storage 4, Red Hat Ceph Storage 5, Red Hat Ceph Storage 6, Red Hat Ceph Storage 7, … · updated 2026-10-21 · vex
• RHSA-2026:83548 · Red Hat · fixed in: Red Hat Ceph Storage 7.1 · released 2026-10-15 · advisory
• RHSA-2026:86618 · Red Hat · fixed in: Red Hat Ceph Storage 9.2 · released 2026-10-21 · advisory