IBM PowerVM Hypervisor FW1120.00, FW1110.00 through FW1110.30, FW1060.00 through FW1060.80, and FW950.00 through FW950.H2 is affected by a vulnerability in partition firmware during network boot. An unauthenticated attacker with access to the same network as a partition undergoing iSCSI SAN network boot can prevent that partition from completing its boot sequence. Other partitions and the managed system are not affected. Only partitions actively performing an iSCSI SAN network boot are affected, resulting in an availability impact.