CVE-2026-86200 Details
Description
PocketMine-MP versions before 5.42.1 contain a denial of service vulnerability in the LoginPacket handler that allows remote attackers to flood warning messages by injecting numerous junk properties into the clientData JWT. Attackers can craft malicious login packets with excessive unknown properties to waste server CPU time and degrade performance.
A denial-of-service vulnerability has been identified in PocketMine-MP versions prior to 5.42.1. The issue arises in the LoginPacket handler, where remote attackers can inject numerous junk properties into the clientData JWT. This injection floods the server with warning messages, wasting CPU time and degrading performance. The vulnerability exploits the JsonMapper's handling of unexpected properties, which, while allowing flexibility for changes from Microsoft, can be abused if not managed carefully.
The vulnerability has been patched in PocketMine-MP version 5.42.1. Instructions for updating can be found in the PocketMine-MP repository on GitHub.
Metrics
CVSS 4.0 Severity and Vector Strings:
VolerionCVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
Volerion
Assessed Sep 9, 2026CISA-ADP
Assessed Sep 18, 2026References to Advisories, Solutions, and Tools
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Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-779 | Logging of Excessive Data | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| PocketMine-MP | < 5.42.1 (semver) |
CPE
Remediation
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Change History
2 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Sep 18, 2026 | CVE Modified | CISA-ADP |
| Sep 9, 2026 | New CVE Received | [email protected] |