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nimiq/core-rs-albatross is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to version 1.3.0, the discovery handler accepts a peer-controlled limit during handshake and stores it unchanged. The immediate HandshakeAck path then honors limit = 0 and returns zero contacts, which makes the session look benign. Later, after the same session reaches Established, the periodic update path computes self.peer list limit.unwrap() as usize - 1. With limit = 0, that wraps to usize::MAX and then in rand 0.9.2, choose multiple() immediately attempts Vec::with capacity(amount), which deterministically panics with capacity overflow. This issue has been patched in version 1.3.0.

**Name of the Vulnerable Software and Affected Versions** nimiq/core-rs-albatross versions prior to 1.1.0 **Description** The issue is related to uncontrolled memory allocation in the `nimiq-network-libp2p` subcrate of nimiq/core-rs-albatross, which can lead to a Denial of Service (DoS) attack. Specifically, the implementation of the `Discovery` network message handling allocates a buffer based on a length value provided by the peer, without enforcing an upper bound. A peer can trigger allocations of up to 4 GB, potentially leading to memory exhaustion and node crashes. As Discovery messages are regularly exchanged for peer discovery, this issue can be exploited repeatedly. **Recommendations** For versions prior to 1.1.0, update to version 1.1.0, which implements a limit to the discovery message size of 1 MB and also resizes the message buffer size incrementally as the data is read. As a temporary workaround, consider restricting the `Discovery` message handling to minimize the risk of exploitation.