CVE-2026-86200Network attack vector

Service degradation via excessive clientData property logging

Published Sep 9, 2026 · Updated Sep 9, 2026

Denial of service in PMMP PocketMine-MP before 5.42.1 allows remote attackers to degrade performance via crafted login packets. The LoginPacket handler's JsonMapper accepts arbitrary unexpected properties in the clientData JWT and emits a warning for each one without a count limit. Any unauthenticated client that can reach the public game port can force repeated logging and CPU use, slowing the server.

CVSS severity6.9
Medium
EPSS probability0.47%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial of service in PMMP PocketMine-MP before 5.42.1 allows remote attackers to degrade performance via crafted login packets. The LoginPacket handler's JsonMapper accepts arbitrary unexpected properties in the clientData JWT and emits a warning for each one without a count limit. Any unauthenticated client that can reach the public game port can force repeated logging and CPU use, slowing the server.

The record

CVE
CVE-2026-86200
Published
Sep 9, 2026
Updated
Sep 9, 2026
Vendor
PMMP
Product
PocketMine-MP
Classifications
CWE-779, T1499
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Sep 9, 2026CVE publishedPublication date reported by the CVE source.
  2. Sep 9, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <5.42.1

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

PMMP · PocketMine-MPversion=0 <5.42.1

Published CVSS scores

6.9GitHubCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-779Logging of Excessive Data
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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