GHSA-27w2-87xv-37c6 nimiq-keys: Unchecked Ed25519 signature length in TaggedPublicKey::verify causes remote node panic via DHT

• crates.io nimiq-keys: <= 0.2.0 (no fix yet)

Impact A malicious network peer can crash any Nimiq full node by publishing a crafted Kademlia DHT record containing a `TaggedSigned` with a signature field whose byte length is not exactly 64. 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. Patches The patch for this vulnerability is formally released as part of v1.4.0. Workarounds No known workarounds. Resources See PR.