Auth bypass in Ceph

CVE-2026-50152

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

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:L/A:L.

EPSS exploit prediction

EPSS: 0.002 (14.8th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 15th percentile — 14.8% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-50152: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: +0.001

Affected products

  • Ceph — versions >= 19.0.0, < 19.2.6, >= 20.0.0, < 20.2.4

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-50152?
CVE-2026-50152 is a critical-severity vulnerability in Ceph, classified under Improper Authorization. CVSS score: 9.1/10. Published 2026-08-28.
How severe is CVE-2026-50152?
Critical severity. CVSS v3 base score is 9.1 out of 10.