GHSA-p62j-hrxm-xcxf
MEDIUMBook page text, count, and author/title length is not limited in PocketMine-MP
Blast Radius
pocketmine/pocketmine-mp🐘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
Players can fill book pages with as many characters as they like; the server does not check this. In addition, the maximum of 50 pages is also not enforced, meaning that players can create "book bombs".
This causes a variety of problems:
- Oversized NBT on the wire costing excess bandwidth for server and client
- Server crashes when saving region-based worlds due to exceeding maximum chunk size of 1 MB (PM3-specific)
- Server crashes if any book page exceeds 32 KiB (due to TAG_String size limit) (PM4-specific)
This does, however, require that an attacker obtain a writable book in the first place in order to exploit the problem.
Patches
The bug has been fixed in 3.26.5 and 4.0.5.
Workarounds
Ban writable books, or use a plugin to cancel PlayerEditBookEvent to cancel the event if strlen(text) > 1024 || mb_strlen(text) > 256.
For more information
If you have any questions or comments about this advisory:
- Email us at [email protected]
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | pocketmine/pocketmine-mp | all versions | 3.26.5 |
| 🐘Packagist | pocketmine/pocketmine-mp | ≥ 4.0.0&&< 4.0.5 | 4.0.5 |
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 3.26.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-p62j-hrxm-xcxf 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-p62j-hrxm-xcxf 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-p62j-hrxm-xcxf. 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-p62j-hrxm-xcxf in your dependencies?
O3 detects GHSA-p62j-hrxm-xcxf across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.