PocketMine-MP server crash with certain invalid JSON payloads in LoginPacket due to dependency vulnerability (again)

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

7.5 · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact An attacker could crash PocketMine-MP by sending malformed JSON in LoginPacket. This happened due to the particular handling of NULL types in the json mapper which accepts NULL type values in typed arrays which PocketMine-MP did not expect. Code processing arrays in the JSON data could then crash due to unexpected NULL elements. Patches This problem was fixed in 5.3.1 and 4.23.1 by updating JsonMapper to include the following commit: pmmp/netresearch-jsonmapper@4f90e8dab1c9df331fad7d3d89823404e882668c An upstream patch for this issue was proposed via https://github.com/cweiske/jsonmapper/pull/211; however, as of 2024-05-15, the patch has not been accepted upstream due to debate about how to deal with the behavior. For now, a fork of JsonMapper is used by PocketMine-MP to workaround the issue. Workarounds A plugin may handle DataPacketReceiveEvent for LoginPacket and check that none of the input arrays contain NULL where it's not expected, but this is rather cumbersome.…

Published by the source

14 Sep 2023, 17:10 UTC

Last modified by the source

23 May 2024, 20:46 UTC

Source last checked

26 Oct 2026, 14:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-92jh-gwch-jq38

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# Patch Next advisory brief: GHSA-92jh-gwch-jq38

Advisory: PocketMine-MP server crash with certain invalid JSON payloads in `LoginPacket` due to dependency vulnerability (again)
IDs: GHSA-92jh-gwch-jq38
Record: https://patchnext.com/advisories/ghsa-92jh-gwch-jq38 (revision 1, source checked 26 Oct 2026, 14:24 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 7.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: pocketmine/pocketmine-mp 5.3.1, 4.23.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist pocketmine/pocketmine-mp: affected >= 5.0.0, <= 5.3.0; <= 4.23.0; fixed in 5.3.1, 4.23.1

## Suggested inspection (read-only)
- Packagist pocketmine/pocketmine-mp: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on pocketmine/pocketmine-mp.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-92jh-gwch-jq38 (GitHub-reviewed advisory GHSA-92jh-gwch-jq38 lists affected ranges: Packagist pocketmine/pocketmine-mp >=5.0.0 =0 <=4.23.0)

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