# CVE-2022-51017: PocketMine-MP input validation bypass in skin data

Source: https://junglewise.ai/threats/cve-2022-51017-pocketmine-mp-input-validation-bypass-in-skin-data  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-09-07. Updated: 2026-09-26  
License: CC BY 4.0 with a link back

CVE-2022-51017 · Severity: high · CVSS 7.5 · Published 2026-09-07

PocketMine-MP is a server software for the Minecraft Pocket Edition game that processes player skin data. Attackers can submit oversized skin field values (skinID, geometryName, geometryData) that bypass length validation, causing the server to crash when attempting to serialize the data—resulting in complete service outage for all players on the affected server.

Technologies: [pocketmine/pocketmine-mp (Packagist)](https://junglewise.ai/threats/technologies/pocketmine-pocketmine-mp). Vendors: [Packagist](https://junglewise.ai/threats/vendors/packagist).

## Quick answers

**Is CVE-2022-51017 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2022-51017 being exploited in the wild.

**How severe is CVE-2022-51017?** High severity, with a CVSS score of 7.5, published 7 September 2026.

**Which products and versions are affected?** pocketmine/pocketmine-mp (Packagist) ECOSYSTEM:introduced=0,fixed=3.26.5.

**Is there a fix for CVE-2022-51017?** Yes. pocketmine/pocketmine-mp (Packagist): upgrade to 3.26.5 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

**How is CVE-2022-51017 attacked?** It is attacked over the network.

**Am I affected by CVE-2022-51017?** Check whether you run pocketmine/pocketmine-mp (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## How to fix

- pocketmine/pocketmine-mp (Packagist): upgrade to 3.26.5 or later

  ```sh
  composer require pocketmine/pocketmine-mp:^3.26.5
  ```


## Technical details

PocketMine-MP versions before 3.26.5 and 4.0.5 fail to validate the maximum length of skin data fields submitted by players, allowing values to exceed the 32767 byte limit imposed by the NBT (Named Binary Tag) TAG_String format. An unauthenticated attacker on the network can send a crafted player join/update packet with oversized skinID, geometryName, or geometryData fields. When the server attempts to serialize this data to NBT format, an exception is triggered, crashing the server process. The vulnerability requires network access to the game server but no prior authentication. Patches are available in versions 3.26.5 and 4.0.5, which add explicit length validation to these fields before serialization.

## Affected products

- PocketMine PocketMine-MP before 3.26.5 and 4.0.5

## Identifiers

- CVE-2022-51017
- GHSA-c6fg-99pr-25m9

## Timeline

- 2022-09-07: disclosed
- 2022: patched: Fixes available in versions 3.26.5 and 4.0.5

## References

- [https://github.com/pmmp/PocketMine-MP/commit/6492cac5c10f9fa8443ceddd2191a7b65b73f601](https://github.com/pmmp/PocketMine-MP/commit/6492cac5c10f9fa8443ceddd2191a7b65b73f601)
- [https://github.com/pmmp/PocketMine-MP/commit/958a9dbf0fe3131ab60319c5a939f5dfbfe5dfbb](https://github.com/pmmp/PocketMine-MP/commit/958a9dbf0fe3131ab60319c5a939f5dfbfe5dfbb)

## Related threats

- [PocketMine-MP denial of service in ModalFormResponsePacket handling](https://junglewise.ai/threats/cve-2026-86204-pocketmine-mp-denial-of-service-in-modalformresponsepacket)
- [PocketMine-MP item duplication via despawn entity attack race condition](https://junglewise.ai/threats/cve-2026-86203-pocketmine-mp-item-duplication-via-despawn-entity-attack-race)
- [PocketMine-MP network amplification in ActorEventPacket](https://junglewise.ai/threats/cve-2026-86202-pocketmine-mp-network-amplification-in-actoreventpacket)
- [PocketMine-MP denial of service in LoginPacket processing](https://junglewise.ai/threats/cve-2026-86201-pocketmine-mp-denial-of-service-in-loginpacket-processing)
- [PocketMine-MP denial of service in LoginPacket handler](https://junglewise.ai/threats/cve-2026-86200-pocketmine-mp-denial-of-service-in-loginpacket-handler)