GHSA-42qm-8v8m-m78c
MEDIUMPocketMine MP vulnerable to uncontrolled resource consumption via mismatched type of 'InventoryTransactionPacket'
Blast Radius
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Description
Impact
A "mismatch" type InventoryTransactionPacket is sent by the client to request a resync of all currently open inventories.
Since PocketMine-MP does not rate-limit these "mismatch" transactions, and the syncing of inventories is not deferred until, e.g. the end of the current tick, they can be used as a very cheap bandwidth multiplier by making the server send out many MB of data (network serialized inventory items can be very large, especially when dealing with large amounts of NBT).
This is not currently known to have been exploited in the wild.
Patches
This problem was fixed in 4.18.0-ALPHA2 by ca6d51498f12427a947467da8fcad7811418e6cc alongside the introduction of the ItemStackRequest system implementation.
Workarounds
Plugins can handle DataPacketReceiveEvent for InventoryTransactionPacket and check if the type is MismatchTransactionData. If it is, apply some kind of rate limit (e.g. max 1 per tick).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pocketmine/pocketmine-mp | all versions | 4.18.0-ALPHA2 |
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 4.18.0-ALPHA2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-42qm-8v8m-m78c 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-42qm-8v8m-m78c 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-42qm-8v8m-m78c. 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-42qm-8v8m-m78c in your dependencies?
O3 detects GHSA-42qm-8v8m-m78c across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.