CVE-2026-52955

A flaw was found in the libceph component of the Linux kernel. A remote attacker could send a specially crafted CEPH_MSG_OSD_MAP message where two internal fields, alg and b->alg, contain differing bucket algorithm values. This discrepancy can lead to an out-of-bounds memory access during processing or memory deallocation, potentially causing a system crash and resulting in a Denial of Service (DoS).

Moderate severity is assigned to this vulnerability because exploitation requires processing malformed network map data received from a compromised or untrusted storage cluster, restricting exposure to active Ceph client environments. In typical Red Hat Enterprise Linux deployments, the libceph driver is not loaded by default and is only engaged when hosts actively mount CephFS or map kernel block storage devices. A successful trigger results in an out-of-bounds memory condition that causes a kernel crash and denial of service, but does not grant arbitrary code execution or compromise host integrity across unaffected non-client systems.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.