CVE-2026-86201 PocketMine-MP before 5.41.1 LogDoS via LoginPacket clientData
Attackers can crash the PocketMine-MP server by sending crafted login packets with complex data structures, causing out-of-memory conditions.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-86201?
CVE-2026-86201 is a high-severity denial of service vulnerability in pmmp PocketMine-MP, published on 9 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
PocketMine-MP before 5.41.1 contains a denial of service vulnerability in LoginPacket processing where large or complex structures in unknown clientData JWT properties cause excessive logging without sanitization. Attackers can send crafted LoginPackets with deeply nested or massive object structures to trigger out-of-memory conditions and crash the server.
Weakness: CWE-400
Which versions are affected by CVE-2026-86201?
2 open source packages ship an affected version, including pocketmine/pocketmine-mp.
| Package | Affected | Fixed in |
|---|---|---|
pocketmine/pocketmine-mp Packagist | All versions | 5.41.1 |
pocketmine/pocketmine-mp Packagist | All versions | 5.41.1 |
How do I fix CVE-2026-86201?
Upgrade pocketmine/pocketmine-mp to 5.41.1 or later.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-86201 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-86201 exists.
Sources
Also known as GHSA-h6rj-3m53-887h, GHSA-qrr8-c2f6-fmqr.