CVE-2023-54392

PocketMine-MP versions >= 4.20.0 before 4.22.3 (and before 5.2.1 in the 5.x branch) fail to validate NBT tag types in BlockActorDataPacket. A player can crash the server by sending a packet containing sign NBT data with an incorrect tag type, triggering an unhandled UnexpectedTagTypeException that terminates the server process.

  • Published Sep 9, 2026
  • CVSS 7.1 high
  • 0.4% chance of exploitation in the next 30 days (EPSS)
  • A fix is available

Affected software

CVE-2023-54392 at the National Vulnerability Database