A double free and use-after-free vulnerability in the RdbLoadDeletedNodes function of the RDB graph decoders (src/serializers/decoders/*/decode_graph_entities.c) in FalkorDB before 4.18.1 allows a remote attacker who can issue Redis replication commands (for example, against an instance with no password configured) to cause a denial of service or execute arbitrary code in the redis-server process by supplying a crafted RDB stream whose deleted-nodes buffer length is not a multiple of sizeof(NodeID). The length check relies on ASSERT(), which is compiled out in release builds, so the function continues after freeing the buffer, reading it and freeing it a second time.
Require authentication on the Redis/FalkorDB instance (requirepass or ACLs), restrict or rename the REPLICAOF/SLAVEOF commands so untrusted clients cannot use them, and do not expose the instance to untrusted networks.
Upgrade FalkorDB to version 4.18.1 or later.