CVE-2025-47270 is a high-severity vulnerability affecting the nimiq/core-rs-albatross project, which is a Rust implementation of the Nimiq Proof-of-Stake blockchain protocol using the Albatross consensus algorithm. The vulnerability resides in the nimiq-network-libp2p subcrate, specifically in the handling of Discovery network messages used for peer discovery. The flaw is an uncontrolled resource consumption issue (CWE-400) where the code allocates a buffer based on a length value provided by a peer without enforcing an upper bound. Since the length is a 32-bit unsigned integer, a malicious peer can request a buffer allocation up to 4 GB in size. This can lead to memory exhaustion on the targeted node, causing crashes or denial of service (DoS). Because Discovery messages are exchanged regularly to maintain peer connectivity, an attacker can repeatedly exploit this to disrupt node availability. The vulnerability affects all versions prior to 1.1.0. The patch released in version 1.1.0 mitigates the issue by capping the maximum Discovery message size to 1 MB and implementing incremental buffer resizing during data reads to prevent large, uncontrolled allocations. No workarounds are currently known, and no exploits have been reported in the wild yet. The CVSS v3.1 score is 7.5 (high), reflecting network attack vector, low attack complexity, no privileges or user interaction required, and impact limited to availability (denial of service).

For European organizations running nodes or infrastructure based on the nimiq/core-rs-albatross implementation, this vulnerability poses a significant risk of service disruption. A successful exploit can cause node crashes or unavailability, impacting blockchain network participation, transaction validation, and consensus operations. This can degrade the reliability and trustworthiness of services relying on Nimiq blockchain technology, including financial applications, decentralized services, or any critical infrastructure using this protocol. Since the attack requires no authentication or user interaction and can be launched remotely over the network, it lowers the barrier for attackers. Repeated exploitation could lead to sustained denial of service, affecting network stability and potentially causing cascading effects in dependent systems. Additionally, memory exhaustion attacks can increase operational costs due to resource overprovisioning or recovery efforts. Although no data confidentiality or integrity impacts are reported, availability degradation alone can have serious business and reputational consequences.

European organizations should immediately upgrade all deployments of nimiq/core-rs-albatross to version 1.1.0 or later, where the vulnerability is patched. Since no workarounds exist, patching is the primary mitigation. Network-level protections can be implemented to limit exposure: deploying rate limiting and traffic filtering on Discovery message traffic to detect and block peers sending abnormally large or frequent messages can reduce attack surface. Monitoring memory usage and process stability of nodes can help detect exploitation attempts early. Organizations should also consider isolating blockchain nodes in segmented network zones with strict ingress controls to minimize exposure to untrusted peers. Regular vulnerability scanning and dependency management practices should be enforced to ensure timely updates. Finally, engaging with the Nimiq community and monitoring threat intelligence feeds for any emerging exploits or attack patterns will help maintain situational awareness.