Summary
PocketMine-MP vulnerable to denial-of-service by sending large modal form responses
Workarounds
Plugins could cancel DataPacketReceiveEvent for this packet, decode the data their way, and then call Player->onFormSubmit() directly, bypassing the vulnerable code.
Impact
Due to a workaround for an old client bug (which has since been fixed), very large JSON payloads in ModalFormResponsePacket were able to cause the server to spend a significant amount of time processing the packet. Large numbers of these packets were able to hog CPU time so as to prevent the server from processing other connections in a timely manner.
GHSA-7M9R-RQ9J-WMMH has a CVSS score of 5.3 (Medium). 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 (4.12.5); 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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The problem has been addressed in 3baa5ab71214f96e6e7ab12cb9beef08118473b5 by removing the workaround code.
Frequently Asked Questions
- What is GHSA-7M9R-RQ9J-WMMH? GHSA-7M9R-RQ9J-WMMH is a medium-severity security vulnerability in pocketmine/pocketmine-mp (composer), affecting versions < 4.12.5. It is fixed in 4.12.5.
- How severe is GHSA-7M9R-RQ9J-WMMH? GHSA-7M9R-RQ9J-WMMH has a CVSS score of 5.3 (Medium). 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-7M9R-RQ9J-WMMH? pocketmine/pocketmine-mp (composer) versions < 4.12.5 is affected.
- Is there a fix for GHSA-7M9R-RQ9J-WMMH? Yes. GHSA-7M9R-RQ9J-WMMH is fixed in 4.12.5. Upgrade to this version or later.
- Is GHSA-7M9R-RQ9J-WMMH exploitable, and should I be worried? Whether GHSA-7M9R-RQ9J-WMMH 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-7M9R-RQ9J-WMMH 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-7M9R-RQ9J-WMMH? Upgrade
pocketmine/pocketmine-mpto 4.12.5 or later.