In SLPJS (npm package slpjs) before version 0.27.4, there is a vulnerability to false-positive validation outcomes for the NFT1 Child Genesis transaction type. A poorly implemented SLP wallet or opportunistic attacker could create a seemingly valid NFT1 child token without burning any of the NFT1 Group token type as is required by the NFT1 specification. This is fixed in version 0.27.4.