CVE-2026-23136

A reliability and availability issue exists in the libceph OSD client sparse read handling. The client tracks progress of a sparse read reply using a separate state machine. When a connection fault happens mid payload or when the sparse read state machine returns an error, the connection is abandoned and later reestablished and pending operations are retried. However the sparse read state was not reset on the fault path. As a result the client can misinterpret the beginning of a new reply as a continuation of the previous reply. This can drive the sparse read machinery into a persistent failure mode that may never recover, producing repeated error messages and repeated socket read failures, effectively preventing successful reads and causing continuous retry loops. From a threat perspective the trigger can be a misbehaving or compromised Ceph OSD server, or a network adversary able to disrupt or truncate traffic, causing fault and retry sequences. The primary impact is denial of service for Ceph clients performing sparse reads.