Is CVE-2023-54355 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2023-54355 being exploited in the wild.

How severe is CVE-2023-54355?

High severity, with a CVSS score of 7.5, published 9 September 2026.

Which products and versions are affected?

pocketmine/pocketmine-mp (Packagist) ECOSYSTEM:introduced=5.2.0,fixed=5.3.1.

Is there a fix for CVE-2023-54355?

Yes. pocketmine/pocketmine-mp (Packagist): upgrade to 5.3.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2023-54355 attacked?

It is attacked over the network.

Am I affected by CVE-2023-54355?

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.

CVE-2023-54355: PocketMine-MP EC key validation bypass in LoginPacket

CVE-2023-54355 · Severity: high · CVSS 7.5 · Published 2026-09-09

PocketMine-MP is a Minecraft server implementation used to host multiplayer game sessions. Versions before 5.3.1 and 4.23.1 fail to properly validate cryptographic keys during player login, allowing attackers to crash servers with specially crafted login packets. This denial-of-service attack requires no authentication and can be exploited by remote unauthenticated users.

Technologies: pocketmine/pocketmine-mp (Packagist). Vendors: Packagist.

Quick answers

Is CVE-2023-54355 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2023-54355 being exploited in the wild.
How severe is CVE-2023-54355?: High severity, with a CVSS score of 7.5, published 9 September 2026.
Which products and versions are affected?: pocketmine/pocketmine-mp (Packagist) ECOSYSTEM:introduced=5.2.0,fixed=5.3.1.
Is there a fix for CVE-2023-54355?: Yes. pocketmine/pocketmine-mp (Packagist): upgrade to 5.3.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2023-54355 attacked?: It is attacked over the network.
Am I affected by CVE-2023-54355?: 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 5.3.1 or later
```
composer require pocketmine/pocketmine-mp:^5.3.1
```

Technical details

The vulnerability is an input validation flaw in the LoginPacket handler. PocketMine-MP uses ECDH (Elliptic Curve Diffie-Hellman) with the secp384r1 curve for deriving symmetric encryption keys after login; however, the server failed to validate that client-supplied identityPublicKey values actually use this curve. An attacker can provide LoginPackets with keys using different curves (e.g. secp256r1) or non-EC key types (e.g. RSA, DH) that still pass JWT signature verification but trigger an uncaught exception during ECDH key derivation. The attack is network-accessible, requires no authentication or user interaction, and crashes the server (denial of service). Patches were released in versions 4.23.1 and 5.3.1.

Affected products

PocketMine PocketMine-MP before 4.23.1 and 5.3.1

Identifiers

CVE-2023-54355
GHSA-79rc-jjh6-rc89

Timeline

2023-09-13: disclosed
2023-09-13: patched: versions 4.23.1 and 5.3.1 released

References

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