Vulnerability · Published Sep 9, 2026 · Assigned by VulnCheck

CVE-2026-86200PocketMine-MP before 5.42.1 LogDoS via LoginPacket clientData JWT

Medium 5.3

In plain English

A medium-severity security flaw in PocketMine-MP from pmmp. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.6%top 49.3% of all CVEs

Exploited in the wildNo reportsCISA SSVC: none

Attack toolingNoneno public tooling known

Official description

PocketMine-MP versions before 5.42.1 contain a denial of service vulnerability in the LoginPacket handler that allows remote attackers to flood warning messages by injecting numerous junk properties into the clientData JWT. Attackers can craft malicious login packets with excessive unknown properties to waste server CPU time and degrade performance.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Packagist	pocketmine/pocketmine-mp	5.42.1	GHSA-xp4f-g2cm-rhg7

Affected products (as reported)

Vendor	Product	Versions
pmmp	PocketMine-MP	0 – before 5.42.1

Weakness: CWE-779 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

GitHub Security Advisory (GHSA-xp4f-g2cm-rhg7) vendor-advisory
Patch Commit patch
VulnCheck Advisory: PocketMine-MP before 5.42.1 LogDoS via LoginPacket clientData JWT third-party-advisory