GHSA-f9jp-856v-8642 is a low-severity (CVSS 3.7) CWE-664 vulnerability in pocketmine/pocketmine-mp. A fix is available for pocketmine/pocketmine-mp — see the affected versions and patch details below.
PocketMine-MP: Player entities can still die and drop items in flaggedForDespawn state
Exploitation Status
No confirmed exploitation observed yet
- CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.
Exploitation and automatability from CISA’s SSVC triage for GHSA-f9jp-856v-8642.
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.
How urgent is this, really
GHSA-f9jp-856v-8642 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 376,715 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
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
Summary
When an entity dies, the entity is flagged for despawn, but remains in the World's entity table, meaning it's still accessible by doing World->getEntity($entityId) and other methods. The same is true of a player when quitting the server.
When a network packet arrives from a client to attack an entity, the handler fetches the entity using World->getEntity($entityId) without any checks if the entity is already marked for despawning. Depending on the timing, the entity in question might already be in the flagged-for-despawn state when the action is processed. This means that the death handler for the entity might be run multiple times, causing loot and XP to be dropped multiple times, among other potential side effects.
Reproducing steps
To reproduce this vulnerability, two clients (Player A and Player B) are required.
Prerequisites: - Player A (Victim): Must have the valuable items to be duplicated in their inventory and 1 HP (to ensure instant death). - Player B (Attacker): Must be equipped with a weapon capable of dealing at least 1 damage.
Steps: 1. Player A and Player B stand next to each other. 2. Player A initiates the disconnect sequence (e.g., clicking "Disconnect" or "Exit to Menu"). 3. Immediately after Player A triggers the disconnect (within a split-second window), Player B must attack and kill Player A. 4. Player A's character dies server-side, and their inventory drops on the ground. 5. Player B collects the dropped items. 6. Player A logs back into the server. 7. Result: Player A still possesses the original items in their inventory, while Player B holds the dropped copies.
Patches
The issue was fixed in https://github.com/pmmp/PocketMine-MP/commit/c0719b76b18f2508143134e79bc9f1aa39109683 by adding checks for flagged-for-despawn entities in several affected locations.
While a cleaner fix would be to have World's various entity accessing methods exclude flagged-for-despawn entities, this was deemed too risky for 5.x as it would require significant internal changes.
Workarounds
Plugins can mitigate this issue on older versions by handling EntityDamageByEntityEvent, checking if the victim entity is flagged for despawn, and if so, cancelling the event.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pocketmine/pocketmine-mp | all versions | 5.39.2composer require pocketmine/pocketmine-mp:^5.39.2 |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update pocketmine/pocketmine-mp to 5.39.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-f9jp-856v-8642 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-f9jp-856v-8642 can be triaged on real exposure rather than presence alone.
Tailored to GHSA-f9jp-856v-8642. 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-f9jp-856v-8642 in your dependencies?
O3 Security finds GHSA-f9jp-856v-8642 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.