CVE-2023-54393: PocketMine-MP before 4.20.5 Denial of Service via LoginPacket

Published Sep 9, 2026
·
Updated

PocketMine-MP versions before 4.20.5 contain a denial of service vulnerability in LoginPacket JSON parsing due to improper validation in the JsonMapper dependency. Attackers can send malformed JSON structures in LoginPacket to crash the server.

Affected Software

1 affected component
PocketMine PocketMine-MP<4.20.5

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Upgrade

    Upgrade PocketMine-MP to a version that resolves this vulnerability.

    Fixed in 4.20.5

Event History

Sep 9, 2026
CVE Published
via MITRE·01:31 PM
Data Sourced
via MITRE·01:31 PM
DescriptionSeverityWeakness

Frequently Asked Questions

1

Which deployments are exposed to this issue?

PocketMine-MP deployments running a version earlier than 4.20.5 are affected. The issue is reachable through LoginPacket processing, so servers that accept client login traffic are exposed.

2

What does an attacker need to exploit it?

An attacker can exploit the issue remotely without authentication or user interaction by sending malformed JSON structures in a LoginPacket. Successful exploitation crashes the server, causing a denial of service.

3

What is the impact of exploitation?

The documented impact is server availability loss: the malformed LoginPacket can crash the PocketMine-MP server. No confidentiality or integrity impact is indicated by the supplied severity vector.

4

What is the remediation?

Upgrade PocketMine-MP to version 4.20.5 or later. Versions before 4.20.5 contain the improper JSON validation issue in the JsonMapper dependency.

Contact

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