How severe is GHSA-c6fg-99pr-25m9?

GHSA-c6fg-99pr-25m9 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by GHSA-c6fg-99pr-25m9?

GHSA-c6fg-99pr-25m9 affects the following packages: pocketmine/pocketmine-mp (Packagist), pocketmine/pocketmine-mp (Packagist). Ecosystems affected: Packagist.

How do I fix GHSA-c6fg-99pr-25m9?

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-c6fg-99pr-25m9 is resolved across your whole dependency graph.

How do I detect GHSA-c6fg-99pr-25m9 in my Packagist dependencies?

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.

How do I mitigate GHSA-c6fg-99pr-25m9 if there is no patch (or I can't update yet)?

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.

Is GHSA-c6fg-99pr-25m9 actively exploited in the wild?

No public exploit code has been indexed for GHSA-c6fg-99pr-25m9 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-c6fg-99pr-25m9?

GHSA-c6fg-99pr-25m9 has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 39th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-c6fg-99pr-25m9?

GHSA-c6fg-99pr-25m9 is classified as Improper Input Validation (CWE-20). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-c6fg-99pr-25m9 published, and has it been updated?

GHSA-c6fg-99pr-25m9 was published on January 6, 2022 and was last updated on September 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘

🐘 Packagist

Not in CISA KEV

HIGH severity

Uncapped length of skin data fields submitted by playersGHSA-c6fg-99pr-25m9

HIGHFix: pmmp/PocketMine-MP@6492cac

GHSA-c6fg-99pr-25m9 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in pocketmine/pocketmine-mp. A fix is available for pocketmine/pocketmine-mp — see the affected versions and patch details below.

Also known asCVE-2022-51017

Published

Jan 6, 2022

Updated

Sep 8, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-c6fg-99pr-25m9.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs39th percentile — riskier than 39% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

GHSA-c6fg-99pr-25m9 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

🐘pocketmine/pocketmine-mp🐘pocketmine/pocketmine-mp

Real-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

Some skin data fields (e.g. skinID, geometryName) are not capped in length. These fields are typically saved in the NBT data of a player when the player quits the server, or during an autosave.

This is problematic due to the 32767 byte limit on TAG_Strings. If any of these fields exceeds 32767 bytes, an exception will be thrown during data saving, which will cause the server to crash.

Other fields (such as skinGeometryData) are also uncapped, but those have a much larger 2 GB length limit, so this is not a concern for those, particularly considering the decompressed packet size limit of 2 MB.

Patches

PM3: 958a9dbf0fe3131ab60319c5a939f5dfbfe5dfbb PM4: 6492cac5c10f9fa8443ceddd2191a7b65b73f601

Workarounds

A plugin may check player skins during PlayerLoginEvent and PlayerSkinChangeEvent and ensure that the offending fields are not larger than 32767 bytes.

For more information

If you have any questions or comments about this advisory:

Email us at [email protected]

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`pocketmine/pocketmine-mp`	all versions	3.26.5`composer require pocketmine/pocketmine-mp:^3.26.5`
🐘Packagist	`pocketmine/pocketmine-mp`	≥ 4.0.0&&< 4.0.5	4.0.5`composer require pocketmine/pocketmine-mp:^4.0.5`

Detection & mitigation playbook

Open-source dependency

Detect
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 3.26.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-c6fg-99pr-25m9 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.

Frequently Asked Questions

### Impact Some skin data fields (e.g. skinID, geometryName) are not capped in length. These fields are typically saved in the NBT data of a player when the player quits the server, or during an autosave. This is problematic due to the 32767 byte limit on `TAG_String`s. If any of these fields exceeds 32767 bytes, an exception will be thrown during data saving, which will cause the server to crash. Other fields (such as skinGeometryData) are also uncapped, but those have a much larger 2 GB length limit, so this is not a concern for those, particularly considering the decompressed packet size