CVE-2026-54542

/// Technical description

Nimiq is a Rust implementation of the Nimiq Proof-of-Stake protocol based on the Albatross consensus algorithm. Prior to 1.6.0, a malicious state-sync peer can crash a syncing node by sending a crafted TrieChunk whose proof contains a TrieNodeChild suffix that is individually valid but exceeds the 63-byte KeyNibbles backing array when combined with the parent key. KeyNibbles::Add in primitives/src/key_nibbles.rs performs the combined slice operation without checking the total length, and the input reaches put_chunk, TrieNodeChild::key, and TrieNodeChild::is_stump before proof.verify, so the attacker does not need a valid cryptographic proof. Exploitation requires the attacker to be selected as the victim's sync peer during state sync. The resulting out-of-bounds panic is transient because the node restarts and resynchronizes. This issue is fixed in version 1.6.0.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References