Summary
NaN/INF in serverbound movement packets can crash clients and servers
Workarounds
Workarounds could be implemented as plugins using DataPacketReceiveEvent to block any inbound movement packets containing bogus values.
For more information
If you have any questions or comments about this advisory:
- Open an issue in pmmp/PocketMine-MP
- Email us at [email protected]
Impact
A malicious client may send a MovePlayerPacket to the server whose position or rotation contains NaN or INF. Since neither the server nor vanilla client handles this properly, a number of interesting side effects come into play.
- The server may crash in various ways if this exploit is used, because some mathematical operations on NaN/INF generate PHP warnings, which are converted into exceptions.
- Clients may not be able to see other clients who have a NaN/INF rotation.
- Clients may also crash in such cases.
The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths. Typical impact: varies by context: data corruption, logic bypass, or denial of service.
GHSA-FM35-JGG3-3GRX has a CVSS score of 7.5 (High). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (3.18.1); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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A patch for this was included in the 3.18.1 release: https://github.com/pmmp/PocketMine-MP/commit/fb20bb38327b4c08ee3976640cd0dd547388a638
Frequently Asked Questions
- What is GHSA-FM35-JGG3-3GRX? GHSA-FM35-JGG3-3GRX is a high-severity improper input validation vulnerability in pocketmine/pocketmine-mp (composer), affecting versions <= 3.18.0. It is fixed in 3.18.1. The application does not adequately validate input before processing it, allowing unexpected values to reach sensitive code paths.
- How severe is GHSA-FM35-JGG3-3GRX? GHSA-FM35-JGG3-3GRX has a CVSS score of 7.5 (High). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of pocketmine/pocketmine-mp are affected by GHSA-FM35-JGG3-3GRX? pocketmine/pocketmine-mp (composer) versions <= 3.18.0 is affected.
- Is there a fix for GHSA-FM35-JGG3-3GRX? Yes. GHSA-FM35-JGG3-3GRX is fixed in 3.18.1. Upgrade to this version or later.
- Is GHSA-FM35-JGG3-3GRX exploitable, and should I be worried? Whether GHSA-FM35-JGG3-3GRX is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether GHSA-FM35-JGG3-3GRX is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix GHSA-FM35-JGG3-3GRX? Upgrade
pocketmine/pocketmine-mpto 3.18.1 or later.