PocketMine-MP server crash with certain invalid JSON payloads in LoginPacket due to dependency vulnerability (3rd time)

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. netresearch/jsonmapper allows objects to be hydrated from scalar types in JSON. However, due to the lack of validation in the code for this feature, it may output improperly initialized objects if applied to objects whose constructors don't handle the input values. Code handling these objects in PocketMine-MP could then crash due to @required properties not being set within the objects. In addition, because JsonMapper does not respect bStrictObjectTypes when processing arrays, it's not possible to avoid the issue by disabling the feature. Due to the relatively high number of security issues arising from unexpected behaviour in JsonMapper, the team is exploring options to replace it. Patches In the meantime, the issue was fixed by pmmp/netresearch-jsonmapper@b96a209f9e8b76b899a0d0918493cd87eb3c02a7 and 6872661fd03649cc7a8762c41c16e9ee5a4de1c9. Workarounds Detecting the malicious data that triggers…

Published by the source

6 Mar 2024, 17:02 UTC

Last modified by the source

15 May 2024, 14:30 UTC

Source last checked

26 Oct 2026, 14:24 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-h6j3-j35f-v2x7

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# Patch Next advisory brief: GHSA-h6j3-j35f-v2x7

Advisory: PocketMine-MP server crash with certain invalid JSON payloads in `LoginPacket` due to dependency vulnerability (3rd time)
IDs: GHSA-h6j3-j35f-v2x7
Record: https://patchnext.com/advisories/ghsa-h6j3-j35f-v2x7 (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 5.11.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist pocketmine/pocketmine-mp: affected < 5.11.1; fixed in 5.11.1

## 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-h6j3-j35f-v2x7 (GitHub-reviewed advisory GHSA-h6j3-j35f-v2x7 lists affected ranges: Packagist pocketmine/pocketmine-mp >=0 <5.11.1)

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