AIKIDO-2026-796232

TL;DR

The nostr-sdk package did not validate the length of the initialization vector decoded from the attacker-controlled ?iv= portion of a NIP-04 encrypted message. The decoded IV was converted to a 16-byte AES-CBC IV type using an asserting conversion, so an IV whose decoded length was not exactly 16 bytes caused a panic before ciphertext decryption. Applications that decrypt untrusted NIP-04 content are affected, including via NIP-47 (Nostr Wallet Connect) where malicious wallet responses reach NIP-04 decryption. A crafted event can terminate the process or disrupt message processing, causing a denial of service. The fix uses a checked conversion so invalid IV lengths return a Malformed error instead of panicking.