GHSA-h87r-f4vc-mchv
HIGHPocketMine-MP vulnerable to improperly checked dropped item count leading to server crash
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
pocketmine/pocketmine-mpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Impact
In 4.18.0, the network handling of inventories was completely revamped. Due to this, a bug was introduced which allowed players to request that the server drop more of an item than they had available in their hotbar.
This did not lead to any duplication issues, but instead led to a server crash, and is believed to have been exploited in the wild.
Patches
This was fixed in 58974765a68f63a9968a7ff3a06f584ff2ee08d2, which was released in 4.18.1.
Workarounds
Handle InventoryTransactionPacket in DataPacketReceiveEvent, and verify that the item count dropped isn't more than the available item count. However, it's complicated to do this, so it's not recommended.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pocketmine/pocketmine-mp | all versions | 4.18.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for pocketmine/pocketmine-mp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update pocketmine/pocketmine-mp to 4.18.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-h87r-f4vc-mchv is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-h87r-f4vc-mchv is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-h87r-f4vc-mchv. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-h87r-f4vc-mchv in your dependencies?
O3 detects GHSA-h87r-f4vc-mchv across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.