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vulnerability / NVI-00007229 / Revision 3

PocketMine-MP has LogDoS by many junk properties in client data JWT in LoginPacket

OSV carries this publisher advisory for pocketmine/pocketmine-mp. This is an aggregated source copy; consult the original publisher and compare update dates.

source listedactiveGHSA-xp4f-g2cm-rhg7CVE-2026-86200

This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.

01 / Meaning

Why it matters

Published affected context helps an owner decide what evidence to gather. This report has not examined your application.

EPSS

0.637%

FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.5056. Missing scores are unknown.

As of · FIRST EPSS

02 / Applicability

The affected context

Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.

pocketmine/pocketmine-mp

source listed
  • ECOSYSTEM: introduced 0; fixed 5.42.1

### Impact Attackers can fill the body of the clientData JWT in LoginPacket with lots of junk properties, causing the server to flood warning messages, as well as wasting CPU time. This happens because the JsonMapper instance used to process the JWT body is configured to warn on unexpected properties instead of rejecting them outright. While this behaviour increases flexibility for random changes introduced by Microsoft, it also creates vulnerabilities if not handled carefully. This vulnerability affects PocketMine-MP servers exposed to a public network where unknown actors may have access. ### Patches This issue was fixed in c1d4a813fb8c21bfd8b9affd040da864b794df71 by restricting the number of unknown properties to 10, and rejecting the packet if this limit is exceeded. This continues to tolerate random additions to the JWT between versions, while preventing the logger from being abused by clients to slow down the server. ### Workarounds Plugins can handle `DataPacketReceiveEvent` to capture `LoginPacket`, and pre-process the clientData JWT to ensure it doesn't have any unusual properties in it. This can be achieved using `JsonMapper` (see the original affected code below) a

GitHub Advisory Database via OSV

03 / Response

What to do next

  1. vendor patch

    The original advisory lists fixed boundaries 5.42.1 for pocketmine/pocketmine-mp. Confirm the publisher’s latest guidance.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. GitHub Advisory Database via OSV

  2. investigate

    Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.

    Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS

A fixed release is not deployment evidence.

Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.

04 / Limits

What this report cannot establish

  • Customer inventory, deployment, reachability and exploitation have not been inspected.
  • NVD lastModified does not establish freshness of every associated CPE record.
Read the collection and interpretation limits ↗

05 / Provenance

Sources you can inspect

Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.

  1. GHSA-xp4f-g2cm-rhg7 ↗

    GitHub Advisory Database via OSV · vendor advisory

    Observed . GitHub-origin advisory, CC-BY-4.0; OSV is an aggregate copy, not independent corroboration.

  2. CVE-2026-86200 ↗

    NIST National Vulnerability Database · official catalog

    Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.

  3. CVE-2026-86200 ↗

    FIRST EPSS · official catalog

    Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.

Public revision history

Only published revisions appear here. Routine fetches do not create a material-change event.

  1. Revision 3 ·

    Source facts changed; compare the preserved prior revision.

  2. Revision 2 ·

    Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.

  3. Revision 1 ·

    First indexed by Null; source disclosure date is shown separately.

Read the public revision data ↗

The next step is private

Bring the question into your environment.

The connected workflow is a development preview for inventory, contextual matching, owner decisions and evidence-based verification. No system-specific result is generated by this page.

See the synthetic workflow preview ↗