CVE-2026-40092 – nimiq-keys: Unchecked Ed25519 signature length in TaggedPublicKey::verify causes remote node panic via DHT

CVE ID :CVE-2026-40092

Published : May 20, 2026, 10:16 p.m. | 42 minutes ago

Description :nimiq-blockchain provides persistent block storage for Nimiq’s Rust implementation. In versions 1.3.0 and below, a malicious network peer can crash any Nimiq full node by publishing a crafted Kademlia DHT record. The maliciously crafted record would contain a TaggedSigned with a signature field whose byte length is not exactly 64 in order to cause a crash. When the victim node’s DHT verifier calls TaggedSigned::verify, execution reaches Ed25519Signature::from_bytes(sig).unwrap() in the TaggedPublicKey implementation for Ed25519PublicKey. The from_bytes call fails because ed25519_zebra::Signature::try_from rejects slices not 64 bytes, and the unwrap() panics. The BLS TaggedPublicKey implementation correctly returns false on error; only the Ed25519 implementation panics. This issue has been fixed in version 1.4.0.

Severity: 7.5 | HIGH

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